a light bulb goes off/on (in someone's head)

idiom

chiefly US, informal
used to say that a person suddenly understands something or has a great idea
After thinking about the problem for several days, a light bulb went off in her head, and she knew how to solve it.

Dictionary Entries Near a light bulb goes off/on (in someone's head)

a light at the end of the tunnel

a light bulb goes off/on (in someone's head)

alighten

Cite this Entry

“A light bulb goes off/on (in someone's head).” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/a%20light%20bulb%20goes%20off%2Fon%20%28in%20someone%27s%20head%29. Accessed 23 Mar. 2023.

Love words? Need even more definitions?

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


What Did You Just Call Me?

  • brown chihuahua sitting on the floor with squinting eyes looking at the camera
  • Before we went to her house, Hannah told us her aunt was a flibbertigibbet.
Spell It

Hear a word and type it out. How many can you get right?

TAKE THE QUIZ
Solve today's spelling word game by finding as many words as you can with using just 7 letters. Longer words score more points.

Can you make 12 words with 7 letters?

PLAY