golf pro vs professional golfer

golf pro and professional golfer both are nouns.

Word	Noun	Adjective	Verb	Adverb
golf pro	Yes	No	No	No
professional golfer	Yes	No	No	No

As nouns, golf pro and professional golfer are synonyms defined as:

golf pro and professional golfer: someone who earns a living by playing or teaching golf

golf pro (noun)	professional golfer (noun)
someone who earns a living by playing or teaching golf	someone who earns a living by playing or teaching golf