tax collector vs taxman

tax collector and taxman both are nouns.

Word	Noun	Adjective	Verb	Adverb
tax collector	Yes	No	No	No
taxman	Yes	No	No	No

As nouns, tax collector and taxman are synonyms defined as:

Other synonyms of tax collector include collector of internal revenue, exciseman, internal revenue agent.

tax collector (noun)	taxman (noun)
someone who collects taxes for the government	someone who collects taxes for the government