part of speech: adjective

definition 1: sure; positive; having no doubt.

  • I’m certain she is still alive.

synonyms: confident, convinced, positive, sure

antonyms: doubtful, hesitant, uncertain, undecided, unsure

definition 2: known to be true without any doubt; definite.

  • It is certain that Earth is round and not flat.

synonyms: definite

antonyms: uncertain

definition 3: specific; fixed.

  • The club admits a certain number of people every year.

synonyms: fixed

antonyms: indefinite, uncertain

definition 4: used to mention a particular person or thing without naming it.

  • A certain person has been asking about you.

synonyms: particular

phrase: for certain

Word Builder: certain +
certainly: yes, indeed; of course; without any doubt.