B, group B, type B - the blood group whose red cells carry the B antigen
B - the 2nd letter of the Roman alphabet
B, B-complex vitamin, B complex, B vitamin, vitamin B, vitamin B complex - originally thought to be a single vitamin but now separated into several B vitamins
B, bacillus - aerobic rod-shaped spore-producing bacterium; often occurring in chainlike formations; found primarily in soil
atomic number 5, B, boron - a trivalent metalloid element; occurs both in a hard black crystal and in the form of a yellow or brown powder
B, Bel - a logarithmic unit of sound intensity equal to 10 decibels
b, barn - (physics) a unit of nuclear cross section; the effective circular area that one particle presents to another as a target for an encounter