B

UK: 'B', 'b': /ˈbiː/ US: 'B', 'b': /bi/ ,'B', 'b': (bē)

Collins Concise English Dictionary © HarperCollins Publishers::

B symbol

1. a note having a frequency of 493.88 hertz (B above middle C) or this value multiplied or divided by any power of 2; the seventh note of the scale of C major
2. the major or minor key having this note as its tonic
3. the supporting or less important of two things
4. a human blood type of the ABO group, containing the B antigen
5. (in Britain) a secondary road
6. boron
7. magnetic flux density
8. bishop
9. (on Brit pencils, signifying degree of softness of lead) black
   Compare H5
10. Also: b bel
11. baryon number
12. a person whose job is in middle management, or who holds an intermediate administrative or professional position
13. (as modifier): a B worker
    See also occupation groupings

abbreviation

1. Belgium (international car registration)

Collins Concise English Dictionary © HarperCollins Publishers::

b, B / biː/ noun (b's, B's, Bs)

1. the second letter and first consonant of the modern English alphabet
2. a speech sound represented by this letter, usually a voiced bilabial stop, as in bell
3. Also: beta the second in a series, esp the second highest grade in an examination