"You canker blossom!" 3 Shakespearean Insults
1540s, Latin, literally "in good faith," ablative of bona fides "good faith" (see faith). Originally used as an adverb, later (18c.) also as an adjective. The opposite is mala fide.
Genuine: “The offer was a bona fide business opportunity: they really meant to carry it through.” From Latin, meaning “in good faith.”