Dictionary

1a

noun, often capitalized often attributive \ˈā\

: 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

plural a's or as\ˈāz\

Full Definition of A

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

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.

First Known Use of A

before 12th century

Other Alphabet Terms

cuneiform, linear, minuscule, pictograph, rune, symbology, wedge

2a

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

—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
—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
:  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 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
—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

3a

preposition also (ˈ)ā\

Definition of A

1
chiefly dialect :  on, in, at
2
:  in, to, or for each <twice a week>
See Usage Discussion at 2a

Origin of A

Middle English, from Old English a-, an, on
First Known Use: before 12th century

4a

verb \ə, (ˌ)a\

Definition of A

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

Origin of A

Middle English, contraction of have
First Known Use: 14th century

5a

preposition \ə\

Definition of A

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

Origin of A

Middle English, by contraction
First Known Use: 15th century

6a

abbreviation

Definition of A

1
absent
2
acceleration
3
acre
4
adult
5
alto
6
anode
7
answer
8
ante
9
anterior
10
are
11
area
12
atto-
13
author

A

abbreviation

Definition of A

1
ace
2
adenine
3
ampere

A

symbol

Definition of A

argon

Å

abbreviation

Definition of Å

angstrom unit
A- Defined for Kids

1a

noun , often cap \ˈā\
plural a's or as \ˈāz\

Definition of A for Kids

1
:  the first letter of the English alphabet
2
:  a grade that shows a student's work is excellent
3
:  a musical note referred to by the letter A

2a

indefinite article \ə, ˈā\

Definition of A for Kids

1
:  someone or something being mentioned for the first time <There's a dog in the yard.>
2
:  the same <two of a kind>
3
:  1any 1 <It's hard for a person to understand.>
4
:  for or from each <an apple a day> <The new theater charges ten dollars a person.>
5
:  2one 3 <a dozen doughnuts> <a week> <This is a third the size of that.> Hint:A is used before words that do not begin with a vowel sound.
Medical Dictionary

a

abbreviation

Medical Definition of A

1
about
2
absent
3
absolute
4
absorbency; absorbent
5
accommodation
6
acetum
7
acid; acidity
8
actin
9
active; activity
10
allergist; allergy
11
alpha
12
anode
13
answer
14
ante
15
anterior
16
aqua
17
area
18
artery
19
asymmetric; asymmetry
July 02, 2015
apprehension Hear it
comprehension or the fear of future evil
Take a 3-minute break and test your skills!
How to use a word that (literally) drives some people nuts.
Test your vocab with our fun, fast game
Ailurophobia, and 9 other unusual fears