Source : WordNet®

BC
     adv : before the Christian era; used following dates before the
           supposed year Christ was born; "in 200 BC" [syn: {B.C.},
            {before Christ}]

Source : Free On-Line Dictionary of Computing

BC
     
        An {arbitrary precision} numeric processing language with
        {C}-like {syntax}.  Traditionally implemented as a front-end
        to {DC}.  There is a {GNU} version called {GNU BC}.
     
        {Unix manual page}: bc(1).