Prefixed to participles and nouns to denote several of the meanings of for(e- pref., especially action 'in advance of' (L 'prae-'), but also action 'on behalf of' (L 'pro-' and English for prep.). So……

One who goes ahead to prepare the way for another, said of John the Baptist. …

One who goes ahead to prepare the way for another, said of John the Baptist. …

(a) With ref. to a specified circumstance, fact, etc.: on account of that, for that reason; (b) with ref. to a concrete object: for it, in exchange for that; (c) ?error for ther-from adv. …