rack one's brain

Definition

To struggle to think of or remember something.

Etymology

Combination of rack (“medieval torture method”), and brain, thus meaning “to cause the mind extreme discomfort”. Variants include rack one's wit (1583) and rack one's memory, as well as cudgel one's brain / cudgel one's brains.

Example Sentences

• "I have been racking my brain all day trying to think of a birthday present for her."
• "Let’s face it – math isn’t for everyone. If you’re done racking your brains over a question based on quadratic equations, differential calculus, or even lengthy word problems, and can’t for the life of you figure out what’s what, then perhaps it’s time you let ChatGPT take up the role of a home tutor."