thinking cap

American  

noun

1. a state of mind marked by reflection or concentration.

   If we put on our thinking caps, we may come up with the answer.

---

thinking cap Idioms  

1. see put on one's thinking cap.

---

Etymology

Origin of thinking cap

First recorded in 1870–75

Example Sentences

Then put on your short-term thinking cap for a moment.

From MarketWatch • Oct. 11, 2025

It’s the biggest week of the high school football season, so let me peek into my crystal ball, put on my thinking cap and come up with some predictions for the biggest games.

From Los Angeles Times • Sep. 28, 2021

There are also branded goodies to be had, such as a decision-making journal and a Farnam Street thinking cap.

From New York Times • Nov. 11, 2018

Most unusual idea: a thinking cap, “for when you don’t have any good ideas.”

From Washington Post • Sep. 15, 2017

Grandpa put his thinking cap on and started mumbling and grumbling.

From "Summer of the Monkeys" by Wilson Rawls