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1. Having or feeling no doubt or uncertainty; confident and assured
   "felt certain of success"; "was certain she had seen it";
   - sure
    
2. Established beyond doubt or question; definitely known
   "what is certain is that every effect must have a cause"; "it is certain that they were on the bus"; "his fate is certain"; "the date for the invasion is certain"
    
3. Definite but not specified or identified
   "set aside a certain sum each week"; "to a certain degree"; "certain breeds do not make good pets"; "certain members have not paid their dues"; "a certain popular teacher"; "a certain Mrs. Jones"
    
4. Certain to occur; destined or inevitable
   "he was certain to fail"; "his fate is certain"; "In this life nothing is certain but death and taxes"; "he faced certain death";
   - sure
    
5. Established irrevocably
   "his fate is certain";
   - sealed
    
6. Reliable in operation or effect
   "a quick and certain remedy";
   - sure
    
7. Exercising or taking care great enough to bring assurance
   "be certain to disconnect the iron when you are through";
   - sure

See also: assurance, authority, bound, careful, cert [Brit, informal], certainty, confidence, confident, convinced, dead cert [Brit, informal], definite, dependable, destined, doomed, fated, foregone conclusion, foreordained, in for, indisputable, positive, predestinate, predestined, predictable, reliable, self-assurance, self-confidence, sure, sure as shooting, sure thing, sureness

Antonym: uncertain, unsure

Encyclopedia: Certain