One entry found for certain.

Entry Word: certain
Function: adjective
Text: 1 known but not named <a certain person told me that today is your birthday>
Synonyms anonymous, one, some, unidentified, unnamed, unspecified
Related Words particular, specific
Near Antonyms known, named, specified
2 having or showing a mind free from doubt <I'm certain that they'll arrive on time>
Synonyms assured, clear, cocksure, confident, doubtless, positive, sanguine, sure
Related Words self-assured, self-conceited, self-confident; decisive, resolute, unfaltering, unhesitating, unwavering
Near Antonyms hesitant, indecisive, wavering; diffident, unassuming
Antonyms doubtful, dubious, uncertain, unsure
3 having been established and usually not subject to change <a certain percentage of the profits will go to charity> -- see FIXED 1
4 impossible to avoid or evade <as he got older, the athlete began to feel the certain effects of the aging process on his body> -- see INEVITABLE
5 not likely to fail <chicken soup is grandma's certain cure for pretty much whatever ails you> -- see INFALLIBLE 2