ostiarius vs Holy Order

ostiarius and Holy Order both are nouns.

Word	Noun	Adjective	Verb	Adverb
ostiarius	Yes	No	No	No
Holy Order	Yes	No	No	No

As nouns, Holy Order is a hypernym of ostiarius; that is, Holy Order is a word with a broader meaning than ostiarius:

ostiarius: the lowest of the minor Holy Orders in the unreformed Western Church but now suppressed by the Roman Catholic Church
Holy Order: (usually plural) the status or rank or office of a Christian clergyman in an ecclesiastical hierarchy

Other hypernyms of ostiarius include clergyman, man of the cloth, reverend, Order.

ostiarius (noun)	Holy Order (noun)
the lowest of the minor Holy Orders in the unreformed Western Church but now suppressed by the Roman Catholic Church	(usually plural) the status or rank or office of a Christian clergyman in an ecclesiastical hierarchy