A

UK: 'A', 'a': strong: /eɪ/, weak: /ə/

US: 'A', 'a': /eɪ/

US: 'A', 'a': (ā; ə; when stressed ā; ä, ô; ə, a, ä)

Collins Concise English Dictionary © HarperCollins Publishers::

A symbol

1. 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
2. the major or minor key having this note as its tonic
3. a human blood type of the ABO group, containing the A antigen
4. (in Britain) a major arterial road
5. ampere(s)
6. absolute (temperature)
7. area
8. (in combination) atomic: an A-bomb, an A-plant
9. a universal affirmative categorical proposition, such as all men are mortal: often symbolized as SaP
   Compare E, I2, O1
10. a person whose job is in top management, or who holds a senior administrative or professional position
11. (as modifier): an A worker
    See also occupation groupings

Collins Concise English Dictionary © HarperCollins Publishers::

a, A / eɪ/ noun (a's, A's, As)

1. the first letter and first vowel of the modern English alphabet
2. any of several speech sounds represented by this letter, in English as in take, bag, calm, shortage, or cobra
3. Also called: alpha the first in a series, esp the highest grade or mark, as in an examination
4. from A to Z ⇒ from start to finish, thoroughly and in detail

a / ə (stressed or emphatic) eɪ/ determiner (indefinite article; used before an initial consonant)

1. used preceding a singular countable noun, if the noun is not previously specified or known: a dog, a terrible disappointment
2. used preceding a noun or determiner of quantity: a cupful, a dozen eggs, a great many, to read a lot
3. preceded by once, twice, several times, etc: each or every; per: once a day, two pounds fifty a pound
4. a certain; one: to change policy at a stroke, a Mr Khan called
5. (preceded by not) any at all: not a hope

Compare an1
See the1

a / ə/ verb

1. an informal or dialect word for have

a / ə/ preposition

1. (usually linked to the preceding noun) an informal form of of

Collins Concise English Dictionary © HarperCollins Publishers::

Å symbol

1. angstrom unit