mistake
noun.
a wrong action attributable to bad judgment or ignorance or inattention
he made a bad mistake|she was quick to point out my errors|I could understand his English in spite of his grammatical faults
Synonym: error, fault
noun.
an understanding of something that is not correct
he wasn't going to admit his mistake|make no mistake about his intentions|there must be some misunderstanding--I don't have a sister
noun.
part of a statement that is not correct
the book was full of errors
Synonym: error
verb.
identify incorrectly
Don't mistake her for her twin sister
Synonym: misidentify
verb.
to make a mistake or be incorrect
Synonym: err, slip