sure, certain, positive, cocksure mean having no doubt or uncertainty. sure usually stresses the subjective or intuitive feeling of assurance. certain may apply to a basing of a conclusion or …

CERTAIN definition: 1. having no doubt or knowing exactly that something is true, or known to be true, correct, exact…. Learn more.

1. (postpositive) positive and confident about the truth of something; convinced: I am certain that he wrote a book. 2. (usually postpositive) definitely known: it is certain that they were on the bus. 3. …

If you are certain about something, you firmly believe it is true and have no doubt about it. If you are not certain about something, you do not have definite knowledge about it.

Jan 20, 2026 · certain (comparative more certain or certainer, superlative most certain or certainest) Sure in one's mind, positive; absolutely confident in the truth of something.

[before a noun] (used before a person or thing that is known in the mind of the speaker or writer, but that is being introduced to the listener): A certain Mr. Smith has been trying to meet you.

According to the U.S. Census Bureau, Certain is ranked #26086 in terms of the most common surnames in America. The Certain surname appeared 939 times in the 2010 census and if you were to sample …

Sure: with an infinitive: as, he is certain to be there to-morrow. Synonyms Undeniable, unquestionable, undoubted, indubitable, indisputable, incontrovertible, inevitable.

CERTAIN definition: free from doubt or reservation; confident; sure. See examples of certain used in a sentence.

certain meaning, definition, what is certain: confident and sure, without any doubts: Learn more.