PRO-

a prefix signifying before, in front, forth, for, in behalf of, in place of, according to; as, propose, to place before; proceed, to go before or forward; project, to throw forward; prologue, part spoken before (the main piece); propel, prognathous; provide, to look out for; pronoun, a word instead of a noun; proconsul, a person acting in place of a consul; proportion, arrangement according to parts.