hymn vs canticle

hymn and canticle both are nouns.

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

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

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

hymn (noun)	canticle (noun)
a song of praise (to God or to a saint or to a nation)	a hymn derived from the Bible

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