From BiblePortal Wikipedia

King James Dictionary [1]

Contra. A Latin preposition signifying against, in opposition, entering into the composition of some English words. It appears to be a compound of con and tra, like intra tra for W. tras. Fr. contre.

Webster's Dictionary [2]

A Latin adverb and preposition, signifying against, contrary, in opposition, etc., entering as a prefix into the composition of many English words. Cf. Counter, adv. & pref.