Definition, Meaning & Synonyms

lose one's marbles

idiom

/lo͞oz wənz ˈmɑrblz/

Definition

To become confused, crazy, or mentally unstable.

Examples

After months of isolation, he started to lose his marbles.
She was so stressed out that her friends joked she was starting to lose her marbles.
If you keep working long hours without a break, you might lose your marbles.

Meaning

This phrase is often used informally to describe when someone is behaving in a strange or irrational way, suggesting they have lost their mental capacity or sanity.