b meaning and definition

B noun

Definition of B (noun)

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