The Collaborative International Dictionary of English v.0.48:
BC \BC\, B C \B. C.\n. before Christ; used in reckoning dates before the supposed year Christ was born, i.e. 1 a. d.. [WordNet 1.5]WordNet (r) 3.0 (2006):
B.C. adv 1: before the Christian era; used following dates before the supposed year Christ was born; "in 200 BC" [syn: BC, B.C., before Christ]