dumb as a rock

In real, traceable use. Part of the curated seed collection; community review is coming.

Meaning · English

Very stupid; dumb as a post.

Where it’s used: Used American English

Examples

Voice assistants are “dumb as a rock,” Satya Nadella, Microsoft’s chief executive, said in an interview this month with The Financial Times, declaring that newer A.I. would lead the way.

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).

Common questions

What does “dumb as a rock” mean?

Very stupid; dumb as a post.

Is “dumb as a rock” formal or informal?

No register label has been reviewed yet — treat it as neutral and check the usage notes above.