(prō) noun plural pros
1. An argument or vote in favor of something: in the phrase pros and cons.
2. One who votes for or favors a proposal: usually in the plural.
—adverb In behalf of; in favor of; for: to argue pro and con. [<L pro for]

(prō) noun plural pros Colloq.
1. A professional athlete.
2. An expert in any field.