2. Acting or done in good faith; sincere, genuine.
3. In plural form, credentials authenticating someone's true identity, background, intentions, and good faith: Henry was a journalist whose bona fides could not be determined.
Genuine or sincere; sincerity. The first expression is used to modify some other word, as in bona fide intentions; the second is generally used as the subject or object of a verb, as in "His bona fides is above reproach", and "We do not question her bona fides." Bona fides is a singular noun.
Bona fide has been used as an adjective phrase in English so often that we all know its pronunciation as, BOH nuh fighd; however, its preferred Latin pronunciation is BAW nuh FIGH duh.
To produce bona fides (BOH nuh FIGH deez), a corrupted Anglicized form, means to show good intentions in dealing with others, show credentials, prove one's identity or ability, etc. and so to indicate that no fraud or deceit is intended or shown.
A bona fide agreement is one that is made in "good faith" which is a Latin phrase taken over bodily from the Latin bona, "good" + fides, "faith".