- Bb [bi:] n plural B's b's1.) [U and C]the second letter of the English alphabet2.) [U and C]3.)a mark given to a student's work to show that it is good but not excellent▪ I got a B in history.4.) [U]used to refer in a short way to one of two different things or people. You can call the first one A.▪ the advantages and disadvantages of choosing product A or B→plan B at ↑plan1 (6)5.) B4509/B1049 etcthe name of a road in Britain that is smaller than an ↑A-road6.) [U]a common type of blood→from A to B at ↑A1 (6)
Dictionary of contemporary English. 2013.