Definitions
1.AdjectiveSure in one's mind, positive; absolutely confident in the truth of something."I was certain of my decision."
2.AdjectiveNot to be doubted or denied; established as a fact."Now that more experiments have been run, the theory is certain and the argument is settled."
3.AdjectiveSure to happen, inevitable; assured."It is certain that Spain will reach the finals. / Spain is now certain to reach the finals. / Spain is now certain of a place in the finals.; Bankruptcy is the certain outcome of your constant gambling and lending."
4.AdjectiveUnfailing; infallible.
5.AdjectiveFixed; regular; determinate."at certain intervals"
6.AdjectiveParticular and definite, but unspecified or unnamed; used to introduce someone or something without going into further detail."Every wine has a certain distinctive character which sets it apart from all others.; Each morning, she would see a certain man rush past her window on his way to work."
7.AdjectiveUsed to denote that the speaker is referring to a specific person or thing that they do not want to name directly, implying that the listener should infer the identity of the referent."I would have been here on time, but a certain someone lost the car keys!"
8.AdjectiveNamed but not previously mentioned."Looking inside the cover, they learned that the book had once belonged to a certain R. Jones."
9.AdjectiveUsed before the name of someone famous that people are expected to know."Since the last British government to make such a proposal was that of a certain Margaret Thatcher, it might not seem unreasonable."
10.AdjectiveDetermined; resolved.
11.DeterminerHaving been determined but not specified."Certain people are good at running."
12.PronounUnnamed or undescribed members (of)."She mentioned a series of contracts, of which certain are not cited."