mistaken

Universal Words adjective 1 [notusuallybeforenoun] ~ (about sb/sth) wrong in your opinion or judgement: You are completely mistaken about Jane. * Unless I'm very much mistaken, that's Paul's wife over there. * I thought I saw someone I knew, but I must have been mistaken. 2 based on a wrong opinion or bad judgement: mistaken views / ideas * I told her my secret in the mistaken belief that I could trust her. mistakenly adverb: He mistakenly believed that his family would stand by him.