-
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:
Manager Dave Roberts said last week that Rushing’s MRI showed a slight UCL tear.
From Los Angeles Times ● Aug. 12, 2026
President Donald Trump has confirmed that he secretly swapped planes as he left a Nato summit in Turkey last month due to a possible threat.
From BBC ● Aug. 12, 2026
The Athletic was the first to report a more specific diagnosis.
From Los Angeles Times ● Aug. 12, 2026
As he left, Turner gave a brief faith-laced pep talk for a group of young Dream Center residents in the audience.
From Los Angeles Times ● Aug. 12, 2026
He publishes a series of articles, in which he describes Tala as a “graveyard of the living dead.”
From "At Last She Stood" by Erin Entrada Kelly
![]()
A spokesperson for StubHub said the operations and support budget doesn’t include some expenses related to fraud protection, technology and engineering.
From The Wall Street Journal ● Aug. 11, 2026
“It’s cool. A lot of guys played against each other in high school.”
From Los Angeles Times ● Aug. 11, 2026
A solar eclipse happens when the Earth, Moon and the Sun align - or almost align.
From BBC ● Aug. 11, 2026
A StubHub spokesperson said about 1% of orders result in a refund.
From The Wall Street Journal ● Aug. 11, 2026
A hundred and sixty acres is a half mile on each side.
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
“Below 1 Å is almost impossible to reach for cryo-EM,” he says.
From Nature ● Jun. 2, 2020
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
Its name comes from the Scottish Gaelic word cheò, meaning mist, and is a reference to the Gaelic name of Isle of Syke - Eilean a' Cheò or Isle of Mist.
From BBC ● Feb. 5, 2024
Some songs—such as “A Guid New Year to ane a’ A’”—were widely recognized.
From National Geographic ● Dec. 27, 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
This masterpiece presents a dachshund with multiple paws a’ flapping looking somewhat between a well-oiled machine and progress itself, as it purposefully walks down the street.
From The Guardian ● Jul. 14, 2018
His employer says he should ride a Volkswagen van called a' combi through a checkpoint about forty minutes north of town.
From "Enrique's Journey" by Sonia Nazario
![]()
Katie Hafner: In fact, they call it kind of a- a triangle of –
From Scientific American ● Sep. 21, 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
You wouldn’t ha’ believed in them first days of April that trouble was a- brewin’ fer all of us—ever’ one was feelin’ good, and we was gettin’ along so fine.”
From "Across Five Aprils" by Irene Hunt
![]()
I don't think the "-e" should eliminate the existing "-o" and the "-a."
From Salon ● Sep. 26, 2022
Primarily, of course, the events are a hugely important commemoration of the Queen's death -a global tribute to the woman who was one of the most recognisable world leaders for so long.
From BBC ● Sep. 17, 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
![]()
"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
The difference between an A- and an A+, according to the report, could depend on how much spring precipitation the region receives.
From Los Angeles Times ● May 12, 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
![]()
From part a. we see that receiving $1.5 million dollars over the course of 20 years is worth $18.693 million dollars in today’s dollars.
From Textbooks ● Mar. 30, 2016
You may notice that the graphs in parts a. and b. are identical.
From Textbooks ● Mar. 30, 2016
Find the derivative of the equation in a. and explain its physical meaning.
From Textbooks ● Mar. 30, 2016
For problems a. and b., let X¯ = the mean stress score for the 75 students.
From Textbooks ● Sep. 19, 2013
“You’re so. You’re just a. Person. You know. Heyl Alfhercht! Your boots are. Boots.”
From Anya and the Nightingale by Sofiya Pasternack
“Versions of this case have played out in federal courts across the country,” Judge Daniel A. Bress wrote for the 9th Circuit on Thursday.
From Los Angeles Times ● Jul. 31, 2026
It is Exhibit A. A guarantee that demands this much luck, money, and endurance before a court will enforce it has not been functioning as a guarantee.
From Slate ● Jul. 28, 2026
It was contained in a since-withdrawn chapter on climate science co-written by ELI “expert” Jessica A. Wentz, a senior fellow at Columbia’s Sabin Center for Climate Change Law.
From The Wall Street Journal ● Jul. 27, 2026
The film from Universal had an "outstanding hold" for its second weekend, industry analyst David A. Gross said, after it dropped only about 30 percent from its $124 million debut.
From Barron's ● Jul. 26, 2026
Working on the railroad was considered a good job, and A. Philip Randolph, perhaps the most important figure in the civil rights movement, was making it a better job.
From "Bad Boy" by Walter Dean Myers
![]()
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
Palestra spent last season on loan at Cagliari and was named Serie A's defender of the year.
From BBC ● Jul. 1, 2026
The A’s plan to move into a new ballpark in Las Vegas in 2028, the next time the teams are scheduled to face off.
From Los Angeles Times ● Jun. 30, 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
Academically he brought home A’s with little effort.
From "Into the Wild" by Jon Krakauer
![]()
As fans grieve Jackie, they wonder what’s next for Shadow and the aerie in Big Bear.
From Los Angeles Times ● Aug. 11, 2026
As Israel’s October election nears, he wants to be seen standing firm for Israel’s security.
From The Wall Street Journal ● Aug. 11, 2026
As it turns out, this is only a golden city for some people – and they're not the ones developers had hoped to attract.
From BBC ● Aug. 11, 2026
As 2025 drew to a close, US tech giant Meta announced that the team behind Manus would join its AI division after the completion of a buyout worth a reported $2 billion.
From Barron's ● Aug. 11, 2026
As time goes on and research improves, the reality of consecutive negative tests becomes increasingly attainable.
From "At Last She Stood" by Erin Entrada Kelly
![]()
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
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
![]()
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
![]()
Dr. Finch rolled out the last name in Maycomb County accents: long a’s, i s, and a pause between syllables.
From "Go Set a Watchman: A Novel" by Harper Lee
![]()
Rushing said that Sunday was the first time he’d felt pain while throwing — “didn’t feel a pop or anything, but felt pretty serious as it kind of tightened up on me a little bit.”
From Los Angeles Times ● Aug. 12, 2026
President Donald Trump has confirmed that he secretly swapped planes as he left a Nato summit in Turkey last month due to a possible threat.
From BBC ● Aug. 12, 2026
Crude prices remain volatile as markets react to developments in the Middle East, says Infinox’s Thadeu Dos Santos in commentary.
From The Wall Street Journal ● Aug. 12, 2026
Both Turner and Kennedy endorsed faith-based recovery programs as alternatives preferred by the administration over “housing first.”
From Los Angeles Times ● Aug. 12, 2026
The Spaniards then set out to convert as many Filipinos as possible to Catholicism.
From "At Last She Stood" by Erin Entrada Kelly
![]()
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.