From PIE *preh₂- (before, forward) — kin to 'first,' 'far,' 'former,' and the Latin prefix 'pro-' behind 'provide' and 'produce.'
Indicating the person or thing that something is intended to benefit or is directed toward.
From Old English 'for' (for, on behalf of, because of, instead of, in place of), from Proto-Germanic *fura (before, in front of), from PIE *preh₂- (before, in front, forward). The same root produced 'fore,' 'before,' 'first,' 'former,' 'far,' 'further,' Latin 'pro' (for, forward), and Greek 'pró' (before). The original spatial sense 'in front of' became 'on behalf of' through the metaphor of standing
'For,' 'first,' 'far,' 'former,' 'forward,' 'pro,' 'project,' 'provide,' 'produce,' and 'problem' all come from PIE *preh₂- (before, forward). 'For' is standing before someone. 'First' is the most before. 'Far' is forward from here. 'Pro-' means forward in Latin. 'Problem' is something thrown forward (pro + ballein). All