mistake (v.)

mid-14c., "to commit an offense;" late 14c., "to misunderstand, misinterpret, take in a wrong sense," from mis- (1) "badly, wrongly" + take (v.) or from a cognate Scandinavian source such as Old Norse mistaka "take in error, miscarry." Perhaps a blend of both words. The more literal sense of "take or choose erroneously" is from late 14c. Meaning "err in advice, opinion, or judgment" is from 1580s. Related: Mistook; mistaking.

mistake (n.)

"an error in action, opinion, or judgment," 1630s, from mistake (v.). The earlier noun was mistaking (c. 1300).

An error is a wandering from truth, primarily in impression, judgment, or calculation and, by extension of the idea, in conduct; it may be a state. A mistake is a false judgment or choice; it does not, as error sometimes does, imply moral obliquity, the defect being placed wholly in the wisdom of the actor, and in its treatment of this defect the word is altogether gentle. [Century Dictionary, 1897]

Meaning "unintended pregnancy" is from 1957. No mistake "no doubt" is by 1818.

Others are reading

Definitions of mistake from WordNet
mistake (n.)
a wrong action attributable to bad judgment or ignorance or inattention;
he made a bad mistake
Synonyms: error / fault
mistake (n.)
an understanding of something that is not correct;
make no mistake about his intentions
he wasn't going to admit his mistake
mistake (n.)
part of a statement that is not correct;
Synonyms: error
mistake (v.)
identify incorrectly;
Don't mistake her for her twin sister
Synonyms: misidentify
mistake (v.)
to make a mistake or be incorrect;
Synonyms: err / slip