usage vs couvade

usage and couvade both are nouns.

Word	Noun	Adjective	Verb	Adverb
usage	Yes	No	No	No
couvade	Yes	No	No	No

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

usage: accepted or habitual practice
couvade: a custom among some peoples whereby the husband of a pregnant wife is put to bed at the time of bearing the child

Other hyponyms of usage include Americanism, Anglicism, Britishism, consuetude, Germanism, habit, use, hijab, rite, ritual.

usage (noun)	couvade (noun)
the act of using	a custom among some peoples whereby the husband of a pregnant wife is put to bed at the time of bearing the child
accepted or habitual practice
the customary manner in which a language (or a form of a language) is spoken or written