Definition of "BC"

BC

adverb
not comparable
1. Initialism of Before Christ.
  Quotations
  [...]Hi vang, King of Yen and of Corea, was defeated, taken and killed in the Year 259 before the Birth of Chriſt, according to the Chineſe Hiſtory, and Tſin vang was acknowledged for Emperor of all China by the Name of Tſin chi hoang ti.]
  , P. Du Halde, “Geographical Obſervations on the Kingdom of Corea”, in The General History Of China‎, 2nd edition, volume IV, page 388
proper noun
1. British Columbia, a Canadian province.
2. Baja California, a Mexican state.
3. Initialism of Boston College.
noun
countable and uncountable, plural BCs
1. Initialism of birth control.
2. (chemistry) Initialism of benzalkonium chloride.
3. (US, navy) Initialism of battlecruiser.
4. (software) Initialism of backward compatibility.
5. Initialism of border collie.
adjective
not comparable
1. (medicine) Initialism of board-certified.