hall porter vs ostiary

hall porter and ostiary both are nouns.

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

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

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

hall porter (noun)	ostiary (noun)
someone who guards an entrance	someone who guards an entrance
	the lowest of the minor Holy Orders in the unreformed Western Church but now suppressed by the Roman Catholic Church