mixologist vs barkeep

mixologist and barkeep both are nouns.

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

As nouns, mixologist and barkeep are synonyms defined as:

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

Other synonyms of mixologist include barkeeper, bartender.

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