door guard vs gatekeeper

door guard and gatekeeper both are nouns.

Word	Noun	Adjective	Verb	Adverb
door guard	Yes	No	No	No
gatekeeper	Yes	No	No	No

As nouns, door guard and gatekeeper are synonyms defined as:

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

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