B

from The American Heritage® Dictionary of the English Language, 5th Edition.

• abbreviation baryon number
• abbreviation Baseball base
• abbreviation Music bass
• abbreviation billion
• abbreviation bishop (chess)

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The second letter of the English alphabet, called bee and written in the Latin script.
• noun The ordinal number second, derived from this letter of the English alphabet, called bee and written in the Latin script.
• noun A personality type of someone who is relaxed and easygoing and able to engage in leisure activities without worrying about work.
• noun An academic grade, better than a C and worse than an A
• noun Signifies a second-tier or second class of a given commodity, group, or category, as in B-movie, B-list, etc.
• noun Alternate or secondary part, as the back side of a phonograph record. Contrasted with A, which is the primary part.
• noun music The seventh note in the C major scale.
• noun computing byte
• noun A blood type that has a specific antigen that aggravates the immune response in people with type A antigen in their blood. They can receive blood from type B or type O, but cannot receive blood from AB or A.
• noun chemistry The symbol for boron.
• noun computing Hexadecimal symbol for 11.
• noun biochemistry IUPAC 1-letter abbreviation for either glutamine or glutamic acid
• abbreviation cricket the number of balls faced by a batsman
• abbreviation The quantity one billion (1,000,000,000), usually used to signify a sum of money
• abbreviation UK The grade of pencil that makes darker marks than grade HB but lighter marks than grade 2B; a pencil with soft lead.
• abbreviation chess Bishop
• noun The second letter of the basic modern Latin alphabet.