b

noun

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

   Synonyms

   • bacillus, B

   Less specific

   • eubacteria, eubacterium, true bacteria

   More specific

   • Bacillus anthracis, anthrax bacillus, Bacillus subtilis, Bacillus globigii, grass bacillus, hay bacillus, Yersinia pestis

   Member of

   • genus Bacillus

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

   Synonyms

   • B-complex vitamin, B complex, vitamin B complex, vitamin B, B vitamin, B

   Less specific

   • water-soluble vitamin

   More specific

   • choline, inositol, pantothenic acid, pantothen, vitamin B1, thiamine, thiamin, aneurin, antiberiberi factor, vitamin B12, cobalamin, cyanocobalamin, antipernicious anemia factor, vitamin B2, vitamin G (more) , riboflavin, lactoflavin, ovoflavin, hepatoflavin, vitamin B6, pyridoxine, pyridoxal, pyridoxamine, adermin, vitamin Bc, vitamin M, folate, folic acid, folacin, pteroylglutamic acid, pteroylmonoglutamic acid, niacin, nicotinic acid, biotin, vitamin H

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

   Synonyms

   • boron, B, atomic number 5

   Less specific

   • chemical element, element

   Made from

   • kernite, borax

4. a logarithmic unit of sound intensity equal to 10 decibels

   Synonyms

   • Bel, B

   Less specific

   • sound unit

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

   Less specific

   • area unit, square measure

6. the 2nd letter of the Roman alphabet

   Synonyms

   • B

   Less specific

   • letter, letter of the alphabet, alphabetic character

   Member of

   • Roman alphabet, Latin alphabet

7. the blood group whose red cells carry the B antigen

   Synonyms

   • B, type B, group B

   Less specific

   • blood group, blood type