/boh"nah fee"des/ ; Eng. /boh"neuh fuy"deez/ or, esp. for 2, /boh"neuh fuydz', bon"euh/
1. ( italics ) Latin. ( used with a sing. v. ) good faith; absence of fraud or deceit; the state of being exactly as claims or appearances indicate: The bona fides of this contract is open to question. Cf. mala fides .
2. ( sometimes italics ) ( used with a pl. v. ) the official papers, documents, or other items that prove authenticity, legitimacy, etc., as of a person or enterprise; credentials: All our bona fides are on file with the SEC.
Usage . BONA FIDES is originally a Latin phrase meaning "good faith." FIDES is singular in Latin and has been used as such in English. At least partially because its -es ending makes BONA FIDES look and sound like a plural, it has developed the plural sense "credentials." This plural use, although criticized by some usage guides, has been increasing in recent decades in all varieties of speech and writing.