fixer vs repairman

fixer and repairman both are nouns.

Word	Noun	Adjective	Verb	Adverb
fixer	Yes	No	No	No
repairman	Yes	No	No	No

As nouns, repairman is a hyponym of fixer; that is, repairman is a word with a more specific, narrower meaning than fixer:

Other hyponyms of fixer include darner, maintenance man, service man.

fixer (noun)	repairman (noun)
synthetic narcotic drug similar to morphine but less habit-forming; used in narcotic detoxification and maintenance of heroin addiction	a skilled worker whose job is to repair things
someone who intervenes with authorities for a person in trouble (usually using underhand or illegal methods for a fee)
a skilled worker who mends or repairs things
a chemical compound that sets or fixes something (as a dye or a photographic image)