ought /ɔːt/verb 4noun 1forms 3 verb4 •to have a duty to do something, used with "to" and a verbI ought to vote in the coming election. •Indicating advisability or prudence.You ought to always stand back from the edge of the platform.Do you think we ought to leave now? •Indicating desirability.He ought to read the book; it was very good. •Indicating likelihood or probability.We ought to arrive by noon if we take the motorway, shouldn't we? noun1 •A statement of what ought to be the case as contrasted with what is the case.Is there a fallacy involved in deriving an ought from a set of exclusively factual or descriptive premises? — 2004 formsoughtest · oughteth · oughts