beat one's brains out


Make a great mental effort to understand, solve, or remember something, as in Joe's beating his brains out to finish this puzzle. Christopher Marlowe used this hyperbolic idiom in The Massacre of Paris (1593): “Guise beats his brains to catch us in his trap.” Also see rack one's brains.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.