mala fides

[mah-lah fee-des; English mey-luh fahy-deez]

noun Latin.

bad faith; intent to cheat or deceive.Compare bona fides(def 1).

bona fides

[boh-nah fee-des; English boh-nuh fahy-deez or especially for 2, boh-nuh-fahydz, bon-uh]

noun

(italics) Latin. (used with a singular verb) 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.Compare mala fides.
(sometimes italics) (used with a plural verb) 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.

Can be confusedbona fide bona fides (see usage note at the current entry)

Usage note

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.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for fides

Historical Examples of fides

"On the tribunal by the trophies of Germanicus, which are near the shrine of the Fides" (May 15, 86).
Pagan and Christian Rome
Rodolfo Lanciani
Fides follows the crowd into the cathedral, to which the scene changes.
The Complete Opera Book
Gustav Kobb
At John's secret command Fides has been brought to the palace.
The Complete Opera Book
Gustav Kobb
Only the fides which is formed and completed in caritas is a virtue (Art. 5).
The Mediaeval Mind (Volume II of II)
Henry Osborn Taylor
The angelic doctor means here living faith, or fides formata.
The Catholic World; Volume I, Issues 1-6
E. Rameur

British Dictionary definitions for fides

bona fides

noun

law good faith; honest intention

Word Origin for bona fides

Latin

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for fides

bona fides

by 1838, English pluralization of bona fide, as though it were a noun meaning "guarantee of good faith."