bona fides

noun

bo·​na fi·​des ˌbō-nə-ˈfī-ˌdēz 

nonstandard

ˈbō-nə-ˌfīdz 

1

: good faith : sincerity

2

: the fact of being genuine

—often plural in construction

3

: evidence of one's good faith or genuineness

—often plural in construction

4

: evidence of one's qualifications or achievements

—often plural in construction

Did you know?

Bona fides looks like a plural word in English, but in Latin it is a singular noun that literally means "good faith." When bona fides entered English, it at first stayed very close to its Latin use, and it also kept its singular form—for example, "a claimant whose bona fides is unquestionable." But in the 20th century, use of bona fides began to widen, and it began to appear with a plural verb in certain contexts, such as "the informant's bona fides were ascertained."

Examples of bona fides in a Sentence

Recent Examples on the Web

Kim, the daughter of Korean immigrants who attended Stanford and has a UC Berkeley law degree, entered the race with little statewide recognition but serious progressive bona fides. — Los Angeles Times, 6 Nov. 2026

Even a temporary press badge required prior approval from the Prime Minister’s Press Office, which, in turn, needed a letter from the American Consulate in Istanbul vouching for my bona fides. — Sarah Matusek, Christian Science Monitor, 2 Nov. 2026

No sooner does Hip 1 walk out after being sold (for $700,000) than the public address announcer runs through the bona fides of Hip 2 as the horse enters the ring. — Dana O’Neil, CNN Money, 30 Oct. 2026

His sons, Norman and Paul, were played by Craig Sheffer and Brad Pitt, the latter in a performance that solidified his acting bona fides after his scene-stealing bit in Thelma & Louise. — Tom Tapp, Deadline, 22 Oct. 2026

Word History

Etymology

Latin, literally, good faith

First Known Use

1665, in the meaning defined at sense 1

Rhymes for bona fides

• disaccharides
• ephemerides
• gangliosides
• insecticides
• neuropeptides
• nucleosides
• nucleotides
• polyamides
• polyimides
• polypeptides
• sulfonamides
• triglycerides

Legal Definition

bona fides

noun

bo·​na fi·​des ˌbō-nə-ˈfī-ˌdēz, commonly ˈbō-nə-ˌfīdz 

: good faith

the fact that the plaintiff conducted an investigation demonstrated its bona fides

—Jeannette Glass Co. v. Indemnity Ins. Co. of North America, 88 A.2d 407 (1952) (dissent)

Etymology

Latin