pro
nounAn argument or consideration in favor of something.
nounOne who supports a proposal or takes the affirmative side in a debate.
adverbIn favor; affirmatively.
adjectiveAffirmative; supporting.
nounA professional, especially in sports.
nounAn expert in a field of endeavor.
adjectiveProfessional.
nounA prefix of Latin or Greek origin, meaning ‘before,’ ‘in front,’ ‘fore,’ ‘forth,’ ‘forward.’ In some words, as proconsul, proprætor, pronoun, etc., it is properly the preposition (Latin pro, for, instead of).
nounA Latin preposition occurring in several phrases used in English.
adverbFor, on, or in behalf of, the affirmative side; — in contrast with