Pro-

[приставка, первая часть сложных слов] 1) про- (образует слова со значением "сторонник") 2) про- (образует слова со значением "заместитель") Например: proconsul — проконсул

Большой англо-русский словарь

Pro-

I. prefix Etymology: New Latin, from Latin, from Greek, before, forward, forth, for, from pro — more at for 1. a. earlier than; prior to; before Example: prothalamion b. rudimentary; prot- Example: pronucleus c. precursory Example: proinsulin 2. a. located in front of or at the front of; anterior to Example: procephalic Example: proventriculus b. front; anterior Example: prothorax 3. projecting Example: prognathous II. prefix Etymology: Latin pro in front of, before, for, forward — more at for 1. taking the place of; substituting for Example: procathedral Example: procaine 2. favoring; supporting; championing Example: pro-American

Merriam-Webster's Collegiate Dictionary