co-respondent vs co-defendant

co-respondent and co-defendant both are nouns.

Word	Noun	Adjective	Verb	Adverb
co-respondent	Yes	No	No	No
co-defendant	Yes	No	No	No

As nouns, co-defendant is a hypernym of co-respondent; that is, co-defendant is a word with a broader meaning than co-respondent:

co-respondent: the codefendant charged with adultery with the estranged spouse in a divorce proceeding
co-defendant: a defendant who has been joined together with one or more other defendants in a single action

Other hypernyms of co-respondent include codefendant.

co-respondent (noun)	co-defendant (noun)
the codefendant charged with adultery with the estranged spouse in a divorce proceeding	a defendant who has been joined together with one or more other defendants in a single action