dumber than a box of rocks
In real, traceable use. Part of the curated seed collection; community review is coming.
Meaning · English
Very stupid.
Register: slang
Where it’s used:
Used
American English
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).
Common questions
What does “dumber than a box of rocks” mean?
Very stupid.
Is “dumber than a box of rocks” formal or informal?
dumber than a box of rocks is generally slang.