canonical hour vs terce

canonical hour and terce both are nouns.

Word	Noun	Adjective	Verb	Adverb
canonical hour	Yes	No	No	No
terce	Yes	No	No	No

As nouns, terce is a hyponym of canonical hour; that is, terce is a word with a more specific, narrower meaning than canonical hour:

canonical hour: (Roman Catholic Church) one of seven specified times for prayer
terce: the third canonical hour; about 9 a.m.

Other hyponyms of canonical hour include matins, morning prayer, prime, tierce, sext, nones, evensong, vespers, complin, compline.

canonical hour (noun)	terce (noun)
(Roman Catholic Church) one of seven specified times for prayer	the third canonical hour; about 9 a.m.