pro | An Elementary Latin Dictionary

pro
prō (archaic collat. form, posi in posimerium; cf. pono, from posino; cf. Gr. ποτί and ποτ with πρ...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.
Pro
·adj A Latin preposition signifying for, before, forth. II. Pro ·adv For, on, or in behalf of, the ...

Webster's Dictionary of the English Language