The dark origin of the idiom rack your brains Image by David Bjorgen via Wikimedia Origin.

Example of idiom rack your brains. I have been racking my brain all day trying to think of place where I kept my car keys. It basically means to think very hard The word rack can be understood to mean work the brain very hard Examples. As to your final question I dont think they have any different meaning its simply a matter of idiom - Use your brain sounds more idiomatic to me but conversely so does rack your brains.

Idiom of the Day rack your brains rack you brain Meaning. Rack your brainsto try very hard to remember or think of something I racked my brains trying to remember his name. She racked her brains but could not remember enough to satisfy the clerk.

Longman Dictionary of Contemporary English. Take a long hard look at sth idiom. The rack was a medieval torture device.

In the cold light of day idiom. Im racking my brains but I just cant think of his name. Christmas is always a hassle for me.

Mull over I need a few days to mull things over before I decide. Shelleys writing this song about being out of work and shes racking her brain trying to come up with a good rhyme for unemployed. Ponder She sat back for a minute to ponder her next move in the game.

The medieval torture device The Rack is the source of the expression rack your brains. Put great effort to think of or remember something. Rack your brain phrase.