Rack your brains


What's the meaning of the phrase 'Rack your brains'?

To rack one’s brains is to strain mentally to recall or to understand something.

What's the origin of the phrase 'Rack your brains'?

The medieval torture device The Rack is the
source of the expression ‘rack your brains‘.

The rack was a medieval torture device. The crude but, one presumes, effective racks often tore the victim’s limbs from their bodies. It isn’t surprising that ‘rack’ was adopted as a verb meaning to cause pain and anguish. Shakespeare was one of many authors who used this; for example, from Twelfth Night, 1602:

“How haue the houres rack’d, and tortur’d me, Since I haue lost thee?”

The term was called on whenever something or someone was under particular stress and all manner of things were said to be ‘racked’; for example, in the Prymmer or boke of priuate prayer nedeful to be vsed of al faythfull Christians, 1553 there’s a reference to the racking, that is, increasing, of land rent:

“They may not racke and stretche oute the rentes of their houses”

The first recorded use of this being specifically applied to brains is in William Beveridge’s Sermons, circa 1680:

“They rack their brains… they hazard their lives for it.”

The same idea was used by the composer William Byrd in 1583 when he wrote:

“Racke not thy wit to winne by wicked waies.”

Trend of rack your brains in printed material over time

Gary Martin is a writer and researcher on the origins of phrases and the creator of the Phrase Finder website. Over the past 26 years more than 700 million of his pages have been downloaded by readers. He is one of the most popular and trusted sources of information on phrases and idioms.

Gary Martin

Writer and researcher on the origins of phrases and the creator of the Phrase Finder website. Over the past 26 years more than 700 million of his pages have been downloaded by readers. He is one of the most popular and trusted sources of information on phrases and idioms.