often capitalized, often attributive
1
a
: the 1st letter of the English alphabet
b
: a graphic representation of this letter
2
: the sixth tone of a C-major scale
3
: a graphic device for reproducing the letter a
4
: one designated a especially as the first in order or class
5
a
: a grade rating a student's work as superior in quality
b
: one graded or rated with an A
6
: something shaped like the letter A
7
capitalized : the one of the four ABO blood groups characterized by the presence of antigens designated by the letter A and by the presence of antibodies against the antigens present in the B blood group
1
—used as a function word before singular nouns when the referent is unspecified
a man overboard
and before number collectives and some numbersa dozen
2
: the same
birds of a feather
swords all of a length
3
a
—used as a function word before a singular noun followed by a restrictive modifier
a man who was here yesterday
b
: any
a person who is sick can't work
c
—used as a function word before a mass noun to denote a particular type or instance
a bronze made in ancient times
d
—used as a function word before a proper noun representing an example or type
the attractions of a Boston or a Cleveland
e
—used as a function word before a proper noun to indicate limited knowledge about the referent
a Mr. Smith called to inquire about the job
f
—used as a function word before a proper noun to distinguish the condition of the referent from a usual, former, or hypothetical condition
a triumphant Ms. Jones greeted her supporters
g
—used before the name of a day of the week to refer to one occurrence of it
Christmas falls on a Tuesday this year.
h
—used before the name of a person [such as a famous artist] when the name is being used to refer to something [such as a painting] created by that person
Her violin is a Stradivarius.
i
—used before a family name to show that someone is a member of that family
To be a Kennedy is to lead two lives … Margaret Carlson
4
—used as a function word with nouns to form adverbial phrases of quantity, amount, or degree
felt a bit tired
In speech and writing a is used before a consonant sound.
Before a vowel sound an is usual
but especially in speech a is used occasionally, more often in some dialects than in others.
Before a consonant sound represented by a vowel letter a is usual
but an also occurs though less frequently now than formerly.
Before unstressed or weakly stressed syllables with initial h both a and an are used in writing.
In the King James Version of the Old Testament and occasionally in writing and speech an is used before h in a stressed syllable.
children are an heritage of the Lord Psalms 127:3 [King James Version]
1
: in, to, or for each
twice a week
2
chiefly dialectal : on, in, at
informal
: of
There are a lot a stairs, but the view at the top is absolutely beautiful. Auli'i Cravalho, quoted in The New York Times
—often attached to the preceding wordBut I did kinda sorta secretly hope to one day be interviewed from Oprah Winfrey's yoga nook. Jennifer SeniorThat's a whole lotta [=lot of] hypothesizin' without a whole lotta science. Rebecca Watson
archaic
: have
I might a had husbands afore now … John Bunyan
Poor Sir William! never shall I forget how he looked whin my lady and he parted. I could a tould the reason, but I'd a cut my tongue out first. Anne Newport Royall
6
chemistry amorphous —usually used in combination
a-Si
2
: in [such] a state or condition
afire
3
: in [such] a manner
aloud
4
: in the act or process of
gone a-hunting
atingle
: not : without
asexual
—a- before consonants other than h and sometimes even before h, an- before vowels and usually before hachromaticahistoricalanastigmaticanhydrous
: replacing carbon especially in a ring
aza-
: oxide
silica
alumina
magnesia
Example Sentences
Noun a word that begins with an a a word that begins with a a song in the key of A She got an A on the exam.
Word History
Etymology
Indefinite article
Middle English, from Old English ān one — more at one
Preposition [1]
Middle English, from Old English a-, an, on
Preposition [2]
Middle English, by contraction
Verb
Middle English, contraction of have
Prefix [1]
Middle English, from Old English
Prefix [2]
Latin & Greek; Latin, from Greek — more at un-
Combining form
perhaps from -a- in ring compounds such as thiazole [in which -a- is the initial of azole]
Noun suffix
New Latin, from -a [as in magnesia]
First Known Use
Noun
before the 12th century, in the meaning defined at sense 1a
Indefinite Article
before the 12th century, in the meaning defined at sense 1
Preposition [1]
before the 12th century, in the meaning defined at sense 2
Preposition [2]
15th century, in the meaning defined above
Verb
14th century, in the meaning defined above
Time Traveler
The first known use of a was before the 12th century
Dictionary Entries Near a
Cite this Entry
“A.” Merriam-Webster.com Dictionary, Merriam-Webster, //www.merriam-webster.com/dictionary/a. Accessed 20 Nov. 2022.
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