¹certain

adjective cer·tain \ˈsər-t^ən\

: not having any doubt about something : convinced or sure

—used with it to say that something is known to be true or correct

—used to refer to something or someone that is not named specifically

Full Definition of CERTAIN

: fixed, settled <a certain percentage of the profit>

: of a specific but unspecified character, quantity, or degree <the house has a certain charm>

a : dependable, reliable <a certain remedy for the disease>

b : known or proved to be true : indisputable <it is certain that we exist>

a : inevitable <the certain advance of age>

b : incapable of failing : destined —used with a following infinitive <she is certain to do well>

: assured in mind or action <I am certain they are right>

— for certain

: as a certainty : assuredly <the cause is not known for certain>

— of a certain age

: of a somewhat advanced age : no longer young <remembered by people of a certain age>

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Origin of CERTAIN

Middle English, from Anglo-French, from Vulgar Latin *certanus, from Latin certus, from past participle of cernere to sift, discern, decide; akin to Greek krinein to separate, decide, judge, Old Irish criathar sieve

First Known Use: 13th century

Related to CERTAIN

Synonyms: anonymous, given, one, some, unidentified, unnamed, unspecified

Antonyms: doubtful, dubious, uncertain, unsure

Synonym Discussion of CERTAIN

sure, certain, positive, cocksure mean having no doubt or uncertainty. sure usually stresses the subjective or intuitive feeling of assurance <felt sure that I had forgotten something>. certain may apply to a basing of a conclusion or conviction on definite grounds or indubitable evidence <police are certain about the cause of the fire>. positive intensifies sureness or certainty and may imply opinionated conviction or forceful expression of it <I'm positive that's the person I saw>. cocksure implies presumptuous or careless positiveness <you're always so cocksure about everything>.