hymn vs dithyramb

hymn and dithyramb both are nouns.

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

As nouns, dithyramb is a hyponym of hymn; that is, dithyramb 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)
dithyramb: (ancient Greece) a passionate hymn (usually in honor of Dionysus)

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

hymn (noun)	dithyramb (noun)
a song of praise (to God or to a saint or to a nation)	(ancient Greece) a passionate hymn (usually in honor of Dionysus)
	a wildly enthusiastic speech or piece of writing

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