mistaken

1. participlepastpast participle of mistake

   I'm frequently mistaken for my brother.

comparative more mistaken · superlative most mistaken

1. Erroneous.

   A mistaken sense of loyalty.

   1 more example

   The statement also recognised that Eta’s “mistakes or mistaken decisions” had led to the deaths of people who had nothing to do with the conflict, both in the Basque country and beyond.

   2018 April 20, Sam Jones, “'We are truly sorry': Eta apologises for four decades of deadly violence”, in The Guardian, →ISSN, archived from the original on 27 Apr 2019

2. oftenHaving an incorrect belief.

   I think you must be (very) much mistaken.

   1 more example

   He admitted he was mistaken about the budget numbers.