certain

/ˈsɜːtən/ adjective

Definition

NO DOUBT [never before noun] › completely sure of something, or knowing without doubt that something is true: [+ (that)] I feel absolutely certain that you're doing the right thing. [+ question word] Nobody was certain how the accident had happened. He was quite certain about/of the thief's identity. → Opposite uncertain

know/say for certain › to know something without doubt: We don't know for certain whether she's coming.

SURE TO HAPPEN › sure to happen, to do something, or to be true: [+ (that)] It now looks certain that she will resign. [+ to do sth] She is certain to do well in the exams. How can we make certain that (= do something to be sure that) she sees the note? One thing is certain. Her attacker knew where she lived.

PARTICULAR [always before noun] › used to refer to a particular person or thing without naming or describing them exactly: The museum is only open at certain times of the day. Certain people react badly to these drugs.

a certain › used before a noun to mean existing, but difficult to describe the exact quality or amount: He's got a certain charm. You have to have a certain amount of courage to perform in public.

certain of formal › used to refer to some of a group of people or things: Certain of you already know the news.

(Definition of certain adjective from the Cambridge Learner's Dictionary © Cambridge University Press)