bona fi ‧ des /ˌbəʊnə ˈfaɪdiːz $ ˌboʊnə-, ˈboʊnə faɪdz/ BrE AmE noun [plural] British English
[ Date: 1800-1900 ; Language: Latin ; Origin: 'good faith' ]
if you check someone’s bona fides, you check that they are who they say they are, and that their intentions are good and honest