taxman vs tax collector

taxman and tax collector both are nouns.

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

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

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

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