An advantage of something, especially when contrasted with its disadvantages (cons).
What are the pros and cons of buying a car?
A person who supports a concept or principle.
In favor of.
He is pro exercise but against physical exertion, quite a conundrum.
A professional sportsman.
Professional.
When it comes to DIY, he's a real pro.
Professional.
He landed a pro mentorship gig.
A prostitute.
A proproctor.