b

noun

1. 1

   the 2nd letter of the Roman alphabet

2. 2

   aerobic rod-shaped spore-producing bacterium; often occurring in chainlike formations; found primarily in soil

3. 3

   (physics) a unit of nuclear cross section; the effective circular area that one particle presents to another as a target for an encounter

4. 4

   the blood group whose red cells carry the B antigen

5. 5

   a logarithmic unit of sound intensity equal to 10 decibels

6. 6

   a trivalent metalloid element; occurs both in a hard black crystal and in the form of a yellow or brown powder

7. 7

   originally thought to be a single vitamin but now separated into several B vitamins