barkeeper vs mixologist

barkeeper and mixologist both are nouns.

Word	Noun	Adjective	Verb	Adverb
barkeeper	Yes	No	No	No
mixologist	Yes	No	No	No

As nouns, barkeeper and mixologist are synonyms defined as:

barkeeper and mixologist: an employee who mixes and serves alcoholic drinks at a bar

Other synonyms of barkeeper include barkeep, bartender.

barkeeper (noun)	mixologist (noun)
an employee who mixes and serves alcoholic drinks at a bar	an employee who mixes and serves alcoholic drinks at a bar