cer·tain / ˈsərtn/ • adj. 1. known for sure; established beyond doubt: she looks certain to win an Oscar. ∎ having complete conviction about something; confident: are you absolutely certain about this?2. specific but not explicitly named or stated: the exercise was causing him a certain amount of pain. ∎ used when mentioning the name of someone not known to the reader or hearer: a certain General Percy captured the town.• pron. (certain of) some but not all: certain of his works have been edited.PHRASES: for certain without any doubt: I don't know for certain.make certain take action to ensure that something happens or is the case: I made certain that our paths would never cross again. ∎ establish whether something is definitely correct or true: he probably knew her, but it didn't do any harm to make certain.
So certainty XIV. — AN. certainté, OF. certaineté.