operetta vs comic opera

operetta and comic opera both are nouns.

Word	Noun	Adjective	Verb	Adverb
operetta	Yes	No	No	No
comic opera	Yes	No	No	No

As nouns, comic opera is a hypernym of operetta; that is, comic opera is a word with a broader meaning than operetta:

operetta: a short amusing opera
comic opera: opera with a happy ending and in which some of the text is spoken

Other hypernyms of operetta include bouffe, opera bouffe, opera comique.

operetta (noun)	comic opera (noun)
a short amusing opera	opera with a happy ending and in which some of the text is spoken