rack your brain
US /ræk jʊər breɪn/
UK /ræk jʊər breɪn/
1.
頭を悩ませる, 頭を絞る
to think very hard to remember something or to find a solution to a problem
:
•
I had to rack my brain to remember her name.
彼女の名前を思い出すために頭を悩ませた。
•
We've been racking our brains all day trying to solve this puzzle.
このパズルを解こうと一日中頭を悩ませている。