dumb as a doornail
In real, traceable use. Part of the curated seed collection; community review is coming.
Meaning · English
Irrefutably or unquestionably dumb.
Register: derogatory
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 “dumb as a doornail” mean?
Irrefutably or unquestionably dumb.
Is “dumb as a doornail” formal or informal?
dumb as a doornail is generally derogatory.