wits' end

• wit's end (US)

wits' end (plural wits' ends)

1. (chiefly British) The limit of one's sanity or mental capacity; the point of desperation.
   • 1699, Edward Taylor, The Poems of Edward Taylor, published 1989, page 136:

     The Seamen they
     Bestir their stumps, and at wits end do weep.
     Wake, Jonas, who saith
     Heave me over deck.

   • 1868 January 4 – June 6, [William] Wilkie Collins, “First Period. The Loss of the Diamond (1848). ”, in The Moonstone. A Romance. , volume II, London: Tinsley Brothers, , published 1868, →OCLC, chapter XXII, page 29:

     He was so eloquent in drawing the picture of his own neglected merits, and so pathetic in lamenting over it when it was done, that I felt quite at my wits' end how to console him, when it suddenly occurred to me that here was a case for the wholesome application of a bit of Robinson Crusoe.

   • 1905 April–October, Upton Sinclair, chapter XVIII, in The Jungle, New York, N.Y.: Doubleday, Page & Company, published 1906 February 26, →OCLC:

     The frightened women were at their wits' end.

   • c. 1911, John Muir, in John Muir and Michael P. Branch, John Muir's Last Journey: South to the Amazon and East to Africa (2002 edition), page 138:

     Our dozen cabin passengers sorely put to wits' end to pass yesterday without cards in observance of the Sabbath.

   • 2010 December 10, Leo Cendrowicz, “Talks on Iran's Nuclear Program Produce ... More Talks”, in Time:

     Yet years of talks, threats and sanctions have failed to halt the program, and officials are at their wits' end on how to wean Iran off its nuclear habit.

• The form wits' end is preferred nearly 3 to 1 in the UK (BNC).
• The form wit's end is preferred more than 2 to 1 in the US (COCA).

• perplexed

• detwins, windest