hymn vs recessional

hymn and recessional both are nouns.

Word	Noun	Adjective	Verb	Adverb
hymn	Yes	No	Yes	No
recessional	Yes	Yes	No	No

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

hymn: a song of praise (to God or to a saint or to a nation)
recessional: a hymn that is sung at the end of a service as the clergy and choir withdraw

Other hyponyms of hymn include dithyramb, doxology, choral, chorale, canticle, hymeneal, paean, pean.

hymn (noun)	recessional (noun)
a song of praise (to God or to a saint or to a nation)	a hymn that is sung at the end of a service as the clergy and choir withdraw
	the withdrawal of the clergy and choir from the chancel to the vestry at the end of a church service

hymn (adjective)	recessional (adjective)
	of or relating to receding

hymn (verb)	recessional (verb)
praise by singing a hymn
sing a hymn