Definition of "pro"

pro¹

/pɹəʊ/

noun
plural pros
1. An advantage of something, especially when contrasted with its disadvantages (cons).
2. A person who supports a concept or principle.
preposition
1. In favor of.

pro²

/pɹəʊ/

noun
plural pros
1. A professional sportsman.
2. (colloquial) Professional.
adjective
comparative more pro, superlative most pro
1. Professional.

pro³

/pɹəʊ/

noun
plural pros
1. (slang) A prostitute.
  Quotations
  Millie was one of the dozen or so pros who had a house at the top of the street.
  1974, "Fynn" (Sydney Hopkins), Mister God, This Is Anna

pro⁴

/pɹəʊ/

noun
plural pros
1. (UK, slang, archaic) A proproctor.

pro⁵

/pɹəʊ/

noun
plural pros
1. (slang, historical) A chemical prophylaxis taken after sex to avoid contracting venereal disease.