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1

a

play
noun \ˈā\

Simple Definition of a

  • : the first letter of the English alphabet

  • : a musical note or key referred to by the letter A : the sixth tone of a C-major scale

  • : a grade that is given to a student for doing excellent work

Full Definition of a

plural a's or asplay \ˈāz\

  1. 1 a :  the 1st letter of the English alphabet b :  a graphic representation of this letter c :  a speech counterpart of orthographic a

  2. 2 :  the sixth tone of a C-major scale

  3. 3 :  a graphic device for reproducing the letter a

  4. 4 :  one designated a especially as the first in order or class

  5. 5 a :  a grade rating a student's work as superior in quality b :  one graded or rated with an A

  6. 6 :  something shaped like the letter A

  7. 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

Examples of a

  1. a word that begins with an a

  2. a word that begins with a

  3. a song in the key of A

  4. She got an A on the exam.



Before 12th Century

First Known Use of a

before 12th century

Other Alphabet Terms


2

a

play
indefinite article \ə, (ˈ)ā, Canada ˈa\

Simple Definition of a

  • —used before singular nouns when the person or thing is being mentioned for the first time

  • —used like one before number words like hundred, thousand, etc.

  • —used like one before number words like third, fortieth, etc.

Full Definition of a

  1. 1 —used as a function word before singular nouns when the referent is unspecified <a man overboard> and before number collectives and some numbers <a dozen>

  2. 2 :  the same <birds of a feather> <swords all of a length>

  3. 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 man 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>

  4. 4 —used as a function word with nouns to form adverbial phrases of quantity, amount, or degree <felt a bit tired>

Usage Discussion of a

In speech and writing a is used before a consonant sound <a door> <a human>. Before a vowel sound an is usual <an icicle> <an honor> but especially in speech a is used occasionally, more often in some dialects than in others <a apple> <a hour> <a obligation>. Before a consonant sound represented by a vowel letter a is usual <a one> <a union> but an also occurs though less frequently now than formerly <an unique> <such an one>. Before unstressed or weakly stressed syllables with initial h both a and an are used in writing <a historic> <an historic>. In the King James Version of the Old Testament and occasionally in writing and speech an is used before h in a stressed syllable <an huntress> <an hundred> <children are an heritage of the Lord — Psalms 127:3(Authorized Version)>.

Origin of a

Middle English, from Old English ān one — more at one


First Known Use: before 12th century


3

a

play
preposition also (ˈ)ā\

Definition of a

  1. 1 chiefly dialect :  on, in, at

  2. 2 :  in, to, or for each <twice a week>



Usage Discussion of a

In speech and writing a is used before a consonant sound <a door> <a human>. Before a vowel sound an is usual <an icicle> <an honor> but especially in speech a is used occasionally, more often in some dialects than in others <a apple> <a hour> <a obligation>. Before a consonant sound represented by a vowel letter a is usual <a one> <a union> but an also occurs though less frequently now than formerly <an unique> <such an one>. Before unstressed or weakly stressed syllables with initial h both a and an are used in writing <a historic> <an historic>. In the King James Version of the Old Testament and occasionally in writing and speech an is used before h in a stressed syllable <an huntress> <an hundred> <children are an heritage of the Lord — Psalms 127:3(Authorized Version)>.

Origin of a

Middle English, from Old English a-, an, on


First Known Use: before 12th century


4

a

play
verb \ə, (ˌ)a\

Definition of a

archaic

  1. :  have <I might a had husbands afore now — John Bunyan>



Origin of a

Middle English, contraction of have


First Known Use: 14th century


5

a

play
preposition \ə\

Definition of a

  1. :  of —often attached to the preceding word <kinda> <lotta>



Origin of a

Middle English, by contraction


First Known Use: 15th century


6

a

abbreviation

Definition of a

  1. 1 absent

  2. 2 acceleration

  3. 3 acre

  4. 4 adult

  5. 5 alto

  6. 6 anode

  7. 7 answer

  8. 8 ante

  9. 9 anterior

  10. 10 are

  11. 11 area

  12. 12 atto-

  13. 13 author




A

abbreviation

Definition of A

  1. 1 ace

  2. 2 adenine

  3. 3 ampere




A

symbol

Definition of A

  1. argon




1

a-

prefix \ə\

Definition of a-

  1. 1 :  on :  in :  at <abed>

  2. 2 :  in (such) a state or condition <afire>

  3. 3 :  in (such) a manner <aloud>

  4. 4 :  in the act or process of <gone a-hunting> <atingle>



Origin of a-

Middle English, from Old English


2

a-

prefix \(ˈ)ā also (ˈ)a or (ˈ)ä\

Definition of a-

  1. :  not :  without <asexual>a- before consonants other than h and sometimes even before h, an- before vowels and usually before h <achromatic> <ahistorical> <anastigmatic> <anhydrous>



Variants of a-

or an- \(ˈ)an\

Origin of a-

Latin & Greek; Latin, from Greek — more at un-


-a-

combining form

Definition of -a-

  1. :  replacing carbon especially in a ring <aza->



Origin of -a-

International Scientific Vocabulary


-a

noun suffix \ə\

Definition of -a

  1. :  oxide <silica>



Origin of -a

New Latin, from -a (as in magnesia)


Å

abbreviation

Definition of Å

  1. angstrom unit




Medical Dictionary

a

abbreviation

Medical Definition of a

  1. 1about

  2. 2absent

  3. 3absolute

  4. 4absorbency; absorbent

  5. 5accommodation

  6. 6acetum

  7. 7acid; acidity

  8. 8actin

  9. 9active; activity

  10. 10allergist; allergy

  11. 11alpha

  12. 12anode

  13. 13answer

  14. 14ante

  15. 15anterior

  16. 16aqua

  17. 17area

  18. 18artery

  19. 19asymmetric; asymmetry




noun \ˈā\

Medical Definition of A

  1. :  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




A

abbreviation

Medical Definition of A

  1. 1adenine

  2. 2ampere




Å

symbol

Medical Definition of Å

  1. angstrom




a-

prefix \(ˈ)ā also (ˈ)a or (ˈ)ä\

Medical Definition of a-

  1. :  not :  without <asexual>a- before consonants other than h and sometimes even before h, an- before vowels and usually before h <achromatic> <anastigmatic> <anhydrous>



Variants of a-

or an- \(ˈ)an\

Learn More about a


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