at one's wits' end, to be(redirected from to be at one's wits' end)
at one's wits' end, to be
To be at a total loss, completely perplexed. “Wits” here means mental capacity or ability to think. The term was used by Chaucer (Troilus and Criseyde) and William Langland (Piers Ploughman) in the late fourteenth century and has been a cliché since the eighteenth century.
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer