doorman vs hall porter

doorman and hall porter both are nouns.

Word	Noun	Adjective	Verb	Adverb
doorman	Yes	No	No	No
hall porter	Yes	No	No	No

As nouns, doorman and hall porter are synonyms defined as:

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

doorman (noun)	hall porter (noun)
someone who guards an entrance	someone who guards an entrance