-
a
aindefinite articlenot any particular or certain one of a class or group.
-
A
Anounthe first letter of the English alphabet, a vowel.
-
Å
Åangstrom.
-
a'
a'adjectiveall.
-
a-
a-a reduced form of the Old English preposition on, meaning “on,” “in,” “into,” “to,” “toward,” preserved before a noun in a prepositional phrase, forming a predicate adjective or an adverbial element (afoot; abed; ashore; aside; away ), or before an adjective (afar; aloud; alow ), as a moribund prefix with a verb (acknowledge ), and in archaic and dialectal use before a present participle in -ing (set the bells aringing ); and added to a verb stem with the force of a present participle (ablaze; agape; aglow; astride; and originally,awry ).
-
-a
-aa plural ending of nouns borrowed from Greek and Latin.
-
A-
A-atomic (used in combination).
-
a.
a.abbreviationyear.
-
A.
A.abbreviationyear.
-
a–
a–A prefix meaning “without” or “not” when forming an adjective (such as amorphous, without form, or atypical, not typical), and “absence of” when forming a noun (such as arrhythmia, absence of rhythm). Before a vowel or h it becomes an– (as in anhydrous, anoxia).
a
1 Americanindefinite article
-
not any particular or certain one of a class or group.
a man; a chemical; a house.
-
a certain; a particular.
one at a time; two of a kind; A Miss Johnson called.
-
another; one typically resembling.
a Cicero in eloquence; a Jonah.
-
one (used before plural nouns that are preceded by a quantifier singular in form): a hundred men (comparehundreds of men ); a dozen times (comparedozens of times ).
-
indefinitely or nonspecifically (used with adjectives expressing number).
a great many years; a few stars.
-
one (used before a noun expressing quantity).
a yard of ribbon; a score of times.
-
any; a single.
not a one.
preposition
preposition
auxiliary verb
abbreviation
noun
-
A's,
plural
-
As,
plural
-
a's,
plural
-
as
plural
-
the first letter of the English alphabet, a vowel.
-
any spoken sound represented by the letter A or a, as in bake, hat, father, or small.
-
something having the shape of an A .
-
a written or printed representation of the letter A or a.
-
a device, as a printer's type, for reproducing the letter A or a.
idioms
-
not know from A to B, to know nothing; be ignorant.
-
from A to Z, from beginning to end; thoroughly; completely.
He knows the Bible from A to Z.
-
the first in order or in a series.
-
Sometimes a
-
(in some grading systems) a grade or mark, as in school or college, indicating the quality of a student's work as excellent or superior.
-
(in some school systems) a symbol designating the first semester of a school year.
-
-
Music.
-
the sixth tone in the scale of C major or the first tone in the relative minor scale, A minor.
-
a string, key, or pipe tuned to this tone.
-
a written or printed note representing this tone.
-
(in the fixed system of solmization) the sixth tone of the scale of C major, called la.
-
the tonality having A as the tonic note.
-
-
Physiology. a major blood group, usually enabling a person whose blood is of this type to donate blood to persons of group A or AB and to receive blood from persons of O or A.
-
Sometimes a the medieval Roman numeral for 50 or 500.
-
Chemistry. (formerly) argon.
-
Chemistry, Physics. mass number.
-
Biochemistry.
-
Logic. Also a universal affirmative.
-
British. a designation for a motion picture recommended as suitable for adults.
-
a proportional shoe width size, narrower than B and wider than AA.
-
a proportional brassiere cup size, smaller than B and larger than AA.
-
a quality rating for a corporate or municipal bond, lower than AA and higher than BBB.
adjective
abbreviation
abbreviation
abbreviation
-
about.
-
acre; acres.
-
active.
-
adjective.
-
alto.
-
ampere; amperes.
-
anonymous.
-
answer.
-
are; ares.
-
Baseball. assist; assists.
abbreviation
abbreviation
abbreviation
-
Absolute.
-
Academy.
-
acre; acres.
-
America.
-
American.
-
angstrom.
-
answer.
-
April.
-
Artillery.
symbol
-
music
-
a note having a frequency of 440 hertz ( A above middle C ) or this value multiplied or divided by any power of 2; the sixth note of the scale of C major
-
a key, string, or pipe producing this note
-
the major or minor key having this note as its tonic
-
-
a human blood type of the ABO group, containing the A antigen
-
(in Britain) a major arterial road
the A3 runs from London to Portsmouth
-
-
a film certified for viewing by anyone, but which contains material that some parents may not wish their children to see
-
( as modifier )
an A film
-
-
mass number
-
the number 10 in hexadecimal notation
-
cards ace
-
chem argon (now superseded by Ar )
-
ampere(s)
-
Also: at. ampere-turn
-
absolute (temperature)
-
(in circuit diagrams) ammeter
-
area
-
(in combination) atomic
an A-bomb
an A-plant
-
chem affinity
-
biochem adenine
-
logic a universal affirmative categorical proposition, such as all men are mortal: often symbolized as SaP Compare E I 2 O 1
-
-
a person whose job is in top management, or who holds a senior administrative or professional position
-
( as modifier ) See also occupation groupings
an A worker
-
abbreviation
determiner
-
used preceding a singular countable noun, if the noun is not previously specified or known
a dog
a terrible disappointment
-
used preceding a proper noun to indicate that a person or thing has some of the qualities of the one named
a Romeo
a Shylock
-
used preceding a noun or determiner of quantity
a cupful
a dozen eggs
a great many
to read a lot
-
used preceding a noun indicating a concrete or abstract thing capable of being divided
half a loaf
a quarter of a minute
-
each or every; per
once a day
fifty pence a pound
-
a certain; one
to change policy at a stroke
a Mr Jones called
-
(preceded by not) any at all
not a hope
symbol
-
acceleration
-
are(s) (metric measure of land)
-
atto-
-
chess See algebraic notation
noun
-
the first letter and first vowel of the modern English alphabet
-
any of several speech sounds represented by this letter, in English as in take, bag, calm, shortage, or cobra
-
Also called: alpha. the first in a series, esp the highest grade or mark, as in an examination
-
from start to finish, thoroughly and in detail
abbreviation
-
acre(s) or acreage
-
America(n)
-
answer
prefix
-
on; in; towards
afoot
abed
aground
aback
-
literary (used before a present participle) in the act or process of
come a-running
go a-hunting
-
in the condition or state of
afloat
alive
asleep
symbol
prefix
verb
preposition
determiner
Grammar
In both spoken and written English the choice of a1 or an 1 is determined by the initial sound of the word that follows. Before a consonant sound, a is used; before a vowel sound, an : a book, a rose; an apple, an opera. Problems arise occasionally when the following word begins with a vowel letter but actually starts with a consonant sound, or vice versa. Some words beginning with the vowel letter u and all words beginning with the vowel letters eu are pronounced with a beginning consonant sound, as if the first letter were y : a union; a European. Some other spellings that begin with a vowel letter may also stand for an initial consonant sound: a ewe; a ewer. The words one and once and all compounds of which they are the first element begin with a w sound: a one-room apartment; a once-famous actor. The names of the consonant letters f, h, l, m, n, r, s, and x are pronounced with a beginning vowel sound. When these letters are used as words or to form words, they are preceded by an : to rent an L-shaped studio; to fly an SST. The names of the vowel letter u and the semivowel letters w and y are pronounced with a beginning consonant sound. When used as words, they are preceded by a : a U-turn; The plumber installed a Y in the line. In some words beginning with the letter h, the h is not pronounced; the words actually begin with a vowel sound: an hour; an honor. When the h is strongly pronounced, as in a stressed syllable at the beginning of a word, it is preceded by a : a history of the Sioux; a hero sandwich. (In former times an was used before strongly pronounced h in a stressed first syllable: an hundred. ) Such adjectives as historic, historical, heroic, and habitual, which begin with an unstressed syllable and often with a silent or weakly pronounced h, are commonly preceded by an, especially in British English. But the use of a rather than an is widespread in both speech and writing: a historical novel; a habitual criminal. Hotel and unique are occasionally preceded by an, but this use is increasingly old-fashioned. Although in some dialects an has yielded to a in all cases, edited writing reflects usage as described above.
Other Word Forms
Noun Inflected Forms
Etymology
Origin of a1
First recorded in 1200–50; Middle English; originally preconsonantal phonetic variant of an 1
Origin of a2
Originally Middle English a, preconsonantal variant of on ( a- 1 ); confused with a 1
Origin of a3
Middle English; unstressed preconsonantal variant of of 1
Origin of a4
First recorded in 1300–50; Middle English; a phonetic variant of have
Origin of a5
First recorded in 1200–50; Middle English a, ha
Origin of a-12
Middle English, late Old English; cf. a 2, nowadays
Origin of a-13
Middle English; see a 3
Origin of a-14
Middle English; Old English a- (unstressed), ǣ-, ā-, ō- (stressed; see abb, woof 1, oakum), rarely or- ( see ordeal), ultimately from unattested Germanic uz- from unstressed Indo-European uss-, from ud-s (these latter two also unattested), akin to out; in some cases confused with a- 4, as in abridge
Origin of a-15
Middle English < Latin ā-, a- (variant of ab- ab- ); in some words < French a- < Latin ab-, as in abridge
Origin of a-16
Middle English, in some words < Middle French a- < Latin ad- prefix or ad preposition ( ad- ), as in abut; in others < Latin a- (variant of ad- ad- ), as in ascend
Origin of -a20
From Latin feminine ending -a, as Claudia, feminine of Claudius; see -a 2
Origin of -a21
Probably generalized from the -a of magnesia
Origin of a.23
< Latin annō, ablative of annus
Origin of a.24
From the Latin word ante
Origin of A.26
< Latin annō, ablative of annus
Origin of A.27
From the Latin word ante
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
Late Friday, talks between the two countries to reach a deal collapsed at the 11th hour, spurring prospects that the dispute between neighbors with almost $900 billion-a-year trading relationship could become an all-out trade war.
From The Wall Street Journal ● Aug. 24, 2026
Zoox assembles them at a plant in Hayward, Calif., that spans 3½ football fields and has the capacity to produce as many as 10,000 robotaxis a year.
From The Wall Street Journal ● Aug. 23, 2026
Zoox rides cost roughly the same as the comfort option of other ride-share services, a spokeswoman said.
From The Wall Street Journal ● Aug. 23, 2026
Amazon is betting it can become a major player in the growing robotaxi market, which Goldman Sachs expects to grow to nearly $19 billion in sales by 2030, from $376 million last year.
From The Wall Street Journal ● Aug. 23, 2026
After a while, one actually succeeds in a dual role.
From "At Last She Stood" by Erin Entrada Kelly
![]()
A look at the top 25 high school football teams in the Southland after Week 0:
From Los Angeles Times ● Aug. 23, 2026
A defeat would have been Liverpool's first on the opening weekend since 2012-13.
From BBC ● Aug. 23, 2026
A diplomatic source and a Syrian government source told AFP that Foreign Minister Assad al-Shaibani met the head of Israel's Mossad intelligence agency Roman Gofman.
From Barron's ● Aug. 23, 2026
A separate insurer that is owned by Amistad, named EquiTrust, also lent large sums to vehicles tied to the other three intermediaries, according to corporate filings.
From The Wall Street Journal ● Aug. 23, 2026
A double-harnessed horse and wagon with a mother, father, and four kids stops.
From "Will’s Race for Home" by Jewell Parker Rhodes
![]()
In the new study, the research team employed state-of-the-art cryo-electron microscopy techniques to capture nine different states associated with the lipid transport and determine structures at 2.4 to 3.1 Å resolution for these states.
From Science Daily ● Dec. 5, 2023
Danish, an often staccato language spoken by only about six million people and whose alphabet includes the letters Æ, Ø and Å, is perhaps an unlikely choice for pop’s next lingua franca.
From New York Times ● Apr. 19, 2023
Note: The length unit angstrom, Å, is often used to represent atomic-scale dimensions and is equivalent to 10−10 m.
From Textbooks ● Feb. 14, 2019
Insight into the Ebola virus nucleocapsid assembly mechanism: crystal structure of Ebola virus nucleoprotein core domain at 1.8 Å resolution.
From Nature ● Nov. 7, 2017
The dark green blobs indicate the position of the line emission from N ii λ ≈ 6,549 Å, Hα and N ii λ ≈ 6,583 Å. Bottom, the line emission and the line fits.
From Nature ● Oct. 15, 2017
Some songs—such as “A Guid New Year to ane a’ A’”—were widely recognized.
From National Geographic ● Dec. 27, 2023
The Scottish government agreed with a recommendation by Sepa which allows Scottish Water to increase abstraction levels from the Allt a' Mhuilinn burn.
From BBC ● Jun. 17, 2023
Whether all this adds up to some big change a’ coming to City Hall, it’s too soon to say.
From Seattle Times ● May 24, 2023
Bob Dylan’s “The Times They Are a’ Changin’” is “a little bit sad and I think it’s about friends,” he wrote.
From Washington Times ● Oct. 8, 2016
‘The voice is right, and your face is no worse than it was, Sam. But I should a’ passed you in the street in that gear.
From "The Return of the King" by J.R.R. Tolkien
![]()
And, uh, you know, it's just a- a very bad situation.
From Scientific American ● May 4, 2023
That giant thing of spices that looks like a-
From Salon ● Mar. 30, 2019
Average sizes are about 2.0 μm and 1.2 μm along the a- and c-axes, respectively. b, AFM height image and height profiles for the MFI nanosheets.
From Nature ● Mar. 14, 2017
The Israeli grandmaster plays the positional side of a Benko Gambit to perfection, building up great pressure on the a- and b-files while the great Benko bishop strafes the White position from g7.
From Washington Times ● May 12, 2015
"Well, don't do it again. Understand? Not at night There's enough silly talk about beasts, without the litthlus seeing you gliding about like a-" The derisive laughter that rose had fear in it and condemnation.
From "Lord of the Flies" by William Golding
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Kroger had proposed selling more than 400 stores to address monopoly concerns -a collection of sitesthe FTC criticised as a "hodgepodge" that did not adequately address concerns.
From BBC ● Feb. 26, 2024
I don't think the "-e" should eliminate the existing "-o" and the "-a."
From Salon ● Sep. 26, 2022
Winston, the No. 1 overall pick from the 2015 draft, has one turnover in the past three games, -a meaningless interception with 1 second remaining in last week’s 28-14 loss to the Saints.
From Washington Times ● Dec. 13, 2018
He needs to grow up or get out -a cancer in the locker room.
From New York Times ● Jan. 9, 2017
"Well, those are not the reasons I'd have given, but . . ." He had touched her cheek, his thumb lightly tracing the line of -a cheek-bone.
From "A Game of Thrones" by George R.R. Martin
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"The All Blacks are a classy outfit, and they'll punish you if you're not on your A- game, and at times we weren't," admitted Irish skipper Dan Sheehan.
From BBC ● Jul. 18, 2026
Yet the average high-school math GPA was an A- for students taking a middle-school remedial course.
From The Wall Street Journal ● Nov. 24, 2025
“Frozen Empire” garnered a B+ CinemaScore from moviegoers, a tick down from the A- score for “Afterlife.”
From Seattle Times ● Mar. 24, 2024
Normally it’s sort of fun to count the A- , B-, and Z-listers shilling for mayonnaise and sneakers.
From Slate ● Feb. 12, 2024
I charged a dollar per assignment and guaranteed at least an A- or the customer was entitled to a full refund.
From "The Glass Castle" by Jeannette Walls
![]()
This makes sense as 1 = loga a means a1 = a. which is true for any a.
From Textbooks ● May 6, 2020
In part a. we showed that RN < 1/2N 2.
From Textbooks ● Mar. 30, 2016
Determine the equation and sketch the trace of the ring torus from a. on the xy-plane.
From Textbooks ● Mar. 30, 2016
Using a. and b. is the train speeding up or slowing down?
From Textbooks ● Mar. 30, 2016
The flutter of cards, motion of hands, of eyelids, the drone of the time-voice in the firehouse ceiling “...one thirty-five. Thursday morning, November 4th,... one thirty-six... one thirty-seven a. m...”
From "Fahrenheit 451" by Ray Bradbury
![]()
"What happens when interest rates go up is that the funding of the deficit becomes more expensive," says economist Mohamed A. El-Erian, a professor at the Wharton School.
From BBC ● Aug. 20, 2026
B. of A. says history suggests the current long-term growth forecast suggests 7% downside risk for the S&P 500 over the next 12 months.
From MarketWatch ● Aug. 19, 2026
"The box office generally slows during the second half of August as kids start returning to school, but right now business remains extremely strong," said industry analyst David A. Gross.
From Barron's ● Aug. 16, 2026
“This quarter is a reflection of the significant progress Biogen has made repositioning the company for long-term growth,” said President and Chief Executive Officer Christopher A. Viehbacher.
From The Wall Street Journal ● Jul. 29, 2026
The three men have a brief yet engaging conversation about clocks and the nature of time before Mr. A. H— makes a polite excuse and fades into the background again.
From "The Night Circus" by Erin Morgenstern
![]()
You know, that’s actually the easiest of all things, if you look, cause it’s such a–
From Slate ● Jan. 22, 2020
The montage ends with a honest rap from Issa: “I don’t want to be here, but my ex won’t take me back. So my broken a– is here, small-talking over apps.”
From Washington Post ● Jul. 28, 2017
We created a– civilian review board, gave them their own detectives.
From Time ● Jan. 17, 2016
MELBER: Now your path here– involved time as a– as a lawyer and a prosecutor.
From MSNBC ● Feb. 12, 2015
But whatever happens, you’ll 240 believe I’ve done my best, won’t you?–even if I’m not a– Promise me straight, you’ll lock up tight every night.”
From Into the Primitive by Robert Ames Bennett
In May, Harvard University faculty voted to approve a 20% cap on the number of A’s per undergraduate course in an effort to curb grade inflation.
From The Wall Street Journal ● Aug. 11, 2026
Louth, 20 years old, said he earned all A’s and one B in his first semester and doubted he would have worked as hard had the classes been pass/fail.
From The Wall Street Journal ● Aug. 11, 2026
Seriously, the dude’s shrieks could be heard echoing in the A’s dugout on the NBC Sports California broadcast of the game.
From Los Angeles Times ● Jul. 1, 2026
In the same way a dismal class performance on a business school exam will still yield some A’s, curves also apply in the stock market when a company’s results aren’t necessarily jumping off the page.
From Barron's ● Jun. 29, 2026
I received straight A’s in my college courses at the end of that semester.
From "The Chosen" by Chaim Potok
![]()
As his stocks started selling off, margin calls came flooding in, and Citadel and Ken Griffin took his lunch money.
From The Wall Street Journal ● Aug. 23, 2026
As usual, some of the greatest heat on Earth will be found at Furnace Creek in Death Valley, where the high was 121 degrees.
From Los Angeles Times ● Aug. 23, 2026
As the outage stretched into a second week, global food charity World Central Kitchen arrived to help people without access to food.
From BBC ● Aug. 23, 2026
As a basher and target of the tokey-wokey, I want to note that she has the numerology wrong.
From The Wall Street Journal ● Aug. 23, 2026
As we head farther north, there might be snow and ice.
From "Will’s Race for Home" by Jewell Parker Rhodes
![]()
Like other Romance languages, Spanish divides most endings of nouns into masculine o’s or feminine a’s.
From Washington Times ● Dec. 12, 2021
And then, every fourth January, we’re suddenly expected to say it, to spell it, to know where to place the u’s and a’s.
From New York Times ● Jan. 19, 2017
But there is no doubt who is the original source of the line, and his last name is spelled with two a's.
From Time Magazine Archive
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The U.A.W. also objects to Hon a's habit of calling its employees "associates," complaining that this is intended to blur labor-management distinctions in the workers' minds.
From Time Magazine Archive
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“Because, see, we’re in Spanish class with all the a's and o’s at the end, and Troy just comes up with this name, Ema, just like that, and boom, it stuck. You see?”
From "Shelter (Book One): A Mickey Bolitar Novel" by Harlan Coben
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Since becoming prime minister, he has sought to diversify Canada’s export-dependent economy away from the U.S. and to build infrastructure projects such as pipelines and ports to get Canadian goods to new markets.
From The Wall Street Journal ● Aug. 24, 2026
U.S. stock-index futures were little changed on Sunday, as it appeared the U.S. was on the verge of an all-out trade war with Canada, one of its biggest trade partners.
From The Wall Street Journal ● Aug. 24, 2026
“I like that it’s private, that there’s not anybody else in the vehicle,” said Lora Harp, 38, who works as a travel agent.
From The Wall Street Journal ● Aug. 23, 2026
He’s also been a major irritant to David Ellison and other top Paramount executives as the actor took a starring role, drumming up opposition in Hollywood to Paramount’s proposed takeover of Warner Bros.
From Los Angeles Times ● Aug. 23, 2026
She volunteers as a secretary for the Patients Federation so she can learn office and secretarial skills.
From "At Last She Stood" by Erin Entrada Kelly
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.