door guard vs porter

door guard and porter both are nouns.

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

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

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

door guard (noun)	porter (noun)
someone who guards an entrance	a very dark sweet ale brewed from roasted unmalted barley
	a person employed to carry luggage and supplies
	a railroad employee who assists passengers (especially on sleeping cars)
	someone who guards an entrance

door guard (verb)	porter (verb)
	carry luggage or supplies