antiphon vs gradual

antiphon and gradual both are nouns.

Word	Noun	Adjective	Verb	Adverb
antiphon	Yes	No	No	No
gradual	Yes	Yes	No	No

As nouns, gradual is a hyponym of antiphon; that is, gradual is a word with a more specific, narrower meaning than antiphon:

antiphon: a verse or song to be chanted or sung in response
gradual: (Roman Catholic Church) an antiphon (usually from the Book of Psalms) immediately after the epistle at Mass

Other hyponyms of antiphon include Improperium.

antiphon (noun)	gradual (noun)
a verse or song to be chanted or sung in response	(Roman Catholic Church) an antiphon (usually from the Book of Psalms) immediately after the epistle at Mass

antiphon (adjective)	gradual (adjective)
	proceeding in small stages
	(of a topographical gradient) not steep or abrupt