mistake

Etymology

From Middle English mistaken, from Old Norse mistaka (“to take in error, to miscarry”); equivalent to mis- + take. Cognate with Icelandic mistaka (“to mistake”), Swedish missta (“to mistake”) (before apocope misstaga). The noun, which replaced earlier mistaking, is derived from the verb.

verb

1. (transitive) To understand wrongly, taking one thing or person for another.
   Sorry, I mistook you for my brother. You look very similar.
   Don't mistake my kindness for weakness.
   The reigning error of his life was, that he mistook the love for the practice of virtue, and was indeed not so much a good man, as the friend of goodness. 1777, Samuel Johnson, “Life of the Author”, in The Works of Richard Savage with an Account of the Life and Writings of the Author, volume I, London: T. Evans, page lxi
2. (transitive, obsolete) To misunderstand (someone).
3. (intransitive, obsolete) To commit an unintentional error; to do or think something wrong.
   1720, Jonathan Swift, “Letter to a Young Clergyman” in The Works of Jonathan Swift, London: Charles Elliot, 1784, Volume 10, pp. 6-7, No gentleman thinks it is safe or prudent to send a servant with a message, without repeating it more than once, and endeavouring to put it into terms brought down to the capacity of the bearer; yet, after all this care, it is frequent for servants to mistake, and sometimes occasion misunderstandings among friends […]
   There is also a chancellor, — no, I mistake, — a chandler and green-grocer, with his hands full of warts; […] 1857, T[héodore] Robertson, “[Charles Saville:[…]] Chapter XXV”, in Synthèse de la langue anglaise (Charles Saville) : Texte anglais avec la traduction française en regard [Synthesis of the English Language (Charles Saville): English Text with Opposite French Translation], 2nd edition, Paris: Librairie française et anglaise de [French and English bookshop of] J.-H. Truchy; Ch. Leroy, successeur [successor]; […], page 240
4. (obsolete, rare) To take or choose wrongly.
   The Spear with erring Haste mistook its way, 1716, Alexander Pope, transl., The Iliad of Homer, London: Bernard Lintott, Volume 2, Book 8, lines 151-152, p. 252

noun

1. An error; a blunder.
   There were too many mistakes in the test, that unfortunately you failed.
   1877, Henry Heth, quoting Robert E. Lee, in "Causes of the Defeat of Gen. Lee's Army at the Battle of GettysburgOpinions of Leading Confederate Soldiers.", Southern Historical Society Papers (1877), editor Rev. J. WM. Jones http://books.google.com/books?id=iDIFAAAAQAAJ&pg=PA292&dq=lee+%22mistakes+were+made%22&hl=en&ei=fchaTbu4L8L98AaVs4n-DQ&sa=X&oi=book_result&ct=result&resnum=3&ved=0CDUQ6AEwAg#v=onepage&q=lee%20%22mistakes%20were%20made%22&f=false After it is all over, as stupid a fellow as I am can see that mistakes were made. I notice, however, that my mistakes are never told me until it is too late.
2. (baseball) A pitch which was intended to be pitched in a hard-to-hit location, but instead ends up in an easy-to-hit place.