A prefix of priority in space or time having especially a meaning of advancing or projecting forward or outward.
From L. pro "in favor of, in place of, before, for," also in some cases from cognate Gk. pro "before, in front of," both from PIE base *por- "forward, through;" cf. Pers. farâ-, as below; Gk. para- "from beside, against, beyond;" Goth. faura "before," O.E. fore "before, for, on account of."
Farâ- "forward, along; above, upon, over; before, foremost, opposing, facing," variant far- intensive prefix "much, abundant; elegantly," from Mid.Pers. fra-; O.Pers. fra- "forward, forth;" Av. frā, fərā-, fra- "forward, forth; before; excessive" (fratəma- "first, front," pouruua- "first," fra-cara- "preceding"); cf. Skt. prá- "before; forward, in fron," prathama- "earliest, initial," pūrva- "first;" Gk. pro; L. pro, as above.