Merriam-Webster Logo
SINCE 1828
Menu
dictionary thesaurus

thinking cap

noun

Definition of thinking cap 

: a state or mood in which one thinks —usually used in the phrase put one's thinking cap on

First Known Use of thinking cap

1827, in the meaning defined above

Keep scrolling for more

Learn More about thinking cap

Share thinking cap

Statistics for thinking cap

Look-up Popularity

Time Traveler for thinking cap

The first known use of thinking cap was in 1827

See more words from the same year

Keep scrolling for more

More Definitions for thinking cap

thinking cap

noun

English Language Learners Definition of thinking cap

—used to refer to the act of trying to solve a problem by thinking carefully about it

See the full definition for thinking cap in the English Language Learners Dictionary

More from Merriam-Webster on thinking cap

See words that rhyme with thinking cap

Comments on thinking cap

What made you want to look up thinking cap? Please tell us where you read or heard it (including the quote, if possible).

Show Comments  Hide Comments 

WORD OF THE DAY

susurrous

full of whispering sounds

Get Word of the Day daily email!

Test Your Vocabulary

Difficult Vocab Quiz

  • the-education-of-achilles-eugne-delacroix
  • Which is a synonym of discomfit?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Add Diction

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Words at Play

Ask the Editors

Word Games