BONA FIDES Meaning of BONA FIDES in English [ ˌbəʊnə'fʌɪdi:z ]■ noun1》 honesty and sincerity of intention. 2》 [treated as plural ] informal a person's credentials.OriginL., lit. 'good faith'. Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004