An Encylopedia Britannica Company

a

833 ENTRIES FOUND:
1 a noun
or A /ˈeɪ/
plural a's or as or A's or As
1 a
noun
or A /ˈeɪ/
plural a's or as or A's or As
Britannica Dictionary definition of A
: the first letter of the English alphabet
[count]
[noncount]
: a musical note or key referred to by the letter A : the sixth tone of a C-major scale
[count]
[noncount]
[count] : a grade that is given to a student for doing excellent work
[noncount] used to refer to the first of two or more people, places, or things that are being considered

an A for effort

see effort

exhibit A

see 2exhibit

from A to Z

: including everything

from (point) A to (point) B

: from one place to another
2 a /ə/ /ˈeɪ/ indefinite article
or an /ən/ /ˈæn/
2 a
/ə/ /ˈeɪ/
indefinite article
or an /ən/ /ˈæn/
Britannica Dictionary definition of A
A is used before a consonant sound.
An is used before a vowel sound.
Note that when a word begins with a vowel letter but is pronounced with a consonant sound, a is used.
When an abbreviation begins with a consonant letter but is pronounced with a vowel sound, an is used.
When a word begins with h but the first syllable of the word is not given primary stress, both a and an are used.
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.
used like one before units of weight, measurement, etc.
: one single : even one used in negative constructions
used before a word or phrase that indicates a type or class of person or thing
often used before noncount nouns that are modified by an adjective or phrase
used like any to refer in a general way to people or things
used before a proper noun to indicate limited knowledge about the person or thing being mentioned
used before a proper noun that is acting as an example or type
used before the name of a day of the week to refer to one occurrence of it
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
used before a family name to show that someone is a member of that family
used before a proper noun referring to a person or thing that has a particular quality
used with words like bit and little to form phrases that describe quantity, amount, or degree
10 
used in phrases that describe how often something occurs, how fast something is going, etc.