transitive verb mistook -·took′, mistaken -·tak′en or Obsoletemistook -·took′, mistaking -·tak′·ing

1. to understand or perceive wrongly; interpret or judge incorrectly mistake someone's motives
2. to take (someone or something) to be another; recognize or identify incorrectly to mistake one twin for the other

Etymology: ME mistaken < ON mistaka, to take wrongly: see mis- & take

intransitive verb

noun

1. a fault in understanding, perception, interpretation, etc.
2. an idea, answer, act, etc. that is wrong; error