mistake -
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"
blot,
smirch,
smear,
stain,
spot an act that brings discredit to the person who does it; "he made a huge blot on his copybook"
mix-up,
confusion a mistake that results from taking one thing to be another; "he changed his name in order to avoid confusion with the notorious outlaw"
incursion the act of entering some territory or domain (often in large numbers); "the incursion of television into the American living room"
mistake -
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"