rack (one's) brain
Informal To think long and hard

[TahlilGaran] Dictionary of Contemporary English ▲

rack brain
rack (your) brain/brains
to think very hard, usually in order to remember something or to find a solution to a problem.
I've been racking my brains but I still can't remember who wrote that play.

rack (your) brains
to try very hard to remember or think of something.
She racked her brains for a subject they could discuss without an argument.

rack (your) brains
to try very hard to remember or think of something.
She racked her brains for a subject they could discuss without an argument.

[TahlilGaran] English Idioms Dictionary ▲

rack one's brain
to try one's best to think about something, to make a great mental effort
I racked my brain for over an hour to try and decide what to do about the new computer.

[TahlilGaran] English Idioms Dictionary ▲

rack one's brain
v. phr. To try your best to think; make a great mental effort; especially: to try to remember something you have known.
Bob racked his brain trying to remember where he left the book.
Susan racked her brain trying to guess whom the valentine came from.
John racked his brain during the test trying to solve the problem.

[TahlilGaran] English Idioms Dictionary ▲