doorman vs gatekeeper

doorman and gatekeeper both are nouns.

Word	Noun	Adjective	Verb	Adverb
doorman	Yes	No	No	No
gatekeeper	Yes	No	No	No

As nouns, doorman and gatekeeper are synonyms defined as:

Other synonyms of doorman include door guard, doorkeeper, hall porter, ostiary, porter.

doorman (noun)	gatekeeper (noun)
someone who guards an entrance	someone who guards an entrance
	someone who controls access to something