-
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:
Regarding the former, Lerner says that “avoiding a recession remains critical to the bull market.”
From MarketWatch ● Oct. 9, 2026
In the olden days, when George Steinbrenner was rattling around in a turtleneck, it would have been different.
From The Wall Street Journal ● Oct. 9, 2026
The technology sector’s P/E multiple has over the same period dropped from 32 to 22, a completely different trajectory from that seen during the dot-com bubble.
From MarketWatch ● Oct. 9, 2026
This is a team that’s supposed to start every spring with a promise to win a ring—or walk straight into the Hudson.
From The Wall Street Journal ● Oct. 9, 2026
One of the first things she writes is an essay about what it means to live in a small, confined community where you interact with the same people every day of your life for years.
From "At Last She Stood" by Erin Entrada Kelly
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A slowdown makes default fears rise and credit spreads widen.
From The Wall Street Journal ● Oct. 9, 2026
A hurricane warning was in effect from Ocean Springs, Mississippi, to the Gulf County Line in Florida, the NHC said in its latest update.
From Barron's ● Oct. 9, 2026
A note published by ING economist Rico Luman on Wednesday highlighted the surge in crude tanker rates that has been triggered by the geopolitical turmoil in the Middle East.
From MarketWatch ● Oct. 9, 2026
A previously unreported Binance document, along with other internal records, reveal the nuts and bolts of how Zanjani’s network used the exchange to move money against the wishes of Western governments.
From The Wall Street Journal ● Oct. 9, 2026
A tour included a mountain climb to the famous Matterhorn....
From "At Last She Stood" by Erin Entrada Kelly
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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
Two or more such β-sheets lie in parallel, 6–12 Å apart.
From Nature ● Nov. 8, 2016
The backbone amide hydrogen bonds maintain the β-strands at a spacing of 4.8 Å in the direction of the fibril.
From Nature ● Nov. 8, 2016
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
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
When April got back to the apartment, there was a' letter waiting for her.
From "The Egypt Game" by Zilpha Keatley Snyder
![]()
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
"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
![]()
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
He needs to grow up or get out -a cancer in the locker room.
From New York Times ● Jan. 9, 2017
But this much you can be sure of -a victory at that level of competition is truly a net positive for months, perhaps years, ahead.
From Washington Times ● May 25, 2016
"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
Though critics savaged the movie, opening night audiences gave it an average grade of A-, according to market research firm CinemaScore.
From The Wall Street Journal ● Jul. 12, 2026
“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
In 1926 it was decided to build A- and B-blocks on the hill, and in 1929 they were completed, along with the chapel and mess hall.
From "Newjack: Guarding Sing Sing" by Ted Conover
![]()
In part a. we showed that RN < 1/2N 2.
From Textbooks ● Mar. 30, 2016
Use your answers to parts a. and d. to determine which of the three options is best.
From Textbooks ● Mar. 30, 2016
Use the answer to part a. to find a general formula for the present value of payments of C dollars received each year over the next n years, assuming an average annual interest rate r.
From Textbooks ● Mar. 30, 2016
Determine the requested vectors and express each of them a. in component form and b. by using the standard unit vectors.
From Textbooks ● Mar. 30, 2016
“You’re so. You’re just a. Person. You know. Heyl Alfhercht! Your boots are. Boots.”
From Anya and the Nightingale by Sofiya Pasternack
One influential model was developed by Krishna Rajagopal, the William A. M. Burden Professor of Physics at MIT, and his collaborators.
From Science Daily ● Oct. 6, 2026
Last week, Justice Samuel A. Alito, a reliable conservative, announced he was withdrawing from the case.
From Los Angeles Times ● Oct. 4, 2026
A. It takes companies several months from deciding they want to go public to listing shares.
From The Wall Street Journal ● Oct. 2, 2026
The research team, which also included Leslie A. Brick from the University of New Mexico, followed 242 children and their mothers for two years.
From Science Daily ● Sep. 29, 2026
After those arrests, a local circuit court judge, James A. Hare, issued an injunction forbidding public gatherings of more than three people.
From "Because They Marched" by Russell Freedman
![]()
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
Sixty percent of grades at Harvard College were A’s in the 2024-25 academic year, up from 24% in 2005-06.
From The Wall Street Journal ● Oct. 8, 2026
With A’s on his report card and the energy and determination to never stop improving, Benson is headed on a path that could take him in many different directions.
From Los Angeles Times ● Sep. 6, 2026
In Las Vegas, Kim envisions baseball fans walking through Bally’s restaurants, bars and entertainment spaces on their way to A’s games, much as fans now stream through the neighborhoods surrounding older urban ballparks.
From The Wall Street Journal ● Aug. 31, 2026
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
I’d earned A’s in every subject except Western Civ.
From "Educated" by Tara Westover
![]()
As more products move through automated warehouses, the Tetris-like task of building pallets should become more precise because software will have more items to choose from, said Montgomery.
From The Wall Street Journal ● Oct. 9, 2026
As a result, American Tower, Crown Castle and SBA should be well-positioned to capture new rental revenue, according to Rezaei.
From MarketWatch ● Oct. 9, 2026
As soybean farmer David Schacht begins his fall harvest, surging diesel and fertilizer costs are fast outpacing his earnings.
From Barron's ● Oct. 9, 2026
As of about 6:45 p.m., the fire had blackened about 140 acres and was 7% contained, according to the California Department of Forestry and Fire Protection.
From Los Angeles Times ● Oct. 9, 2026
As he talked, he was harnessing the donkey.
From "Adventures of Don Quixote" by Argentina Palacios
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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
![]()
Still, Lerner emphasizes that, as the bull market completes its fourth year, “age alone is not a reason to become defensive.”
From MarketWatch ● Oct. 9, 2026
Elon Musk’s SpaceX is bidding for licenses and could take on giants such as AT&T, Verizon and T-Mobile US.
From The Wall Street Journal ● Oct. 9, 2026
Inevitably, such an anniversary will have some worrying that the bull is showing signs of age, with chances of its demise increasing as it trundles on.
From MarketWatch ● Oct. 9, 2026
The companies are collecting on record-high margins for diesel and other fuels as global supplies shrink and prices skyrocket.
From The Wall Street Journal ● Oct. 9, 2026
In October 1953, as the deportation hearings to send Joey back to the Philippines gain momentum, Joey writes an editorial for The Star, detailing her uphill battle for citizenship.
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.