dumb as a doornail
Lacking all intelligence
Dumb as a doornail means completely silent or, more commonly, utterly stupid.
The phrase echoes the older "dead as a doornail," borrowing its emphatic rhythm.
Doornails have no special connection to silence or stupidity—the phrase works through sound and tradition rather than logic: He just sat there dumb as a doornail while they robbed him blind.
- airheadFoolish, flighty person
- blockheadStupid, foolish person
- boneheadFoolish or stupid person
- thickheadedStubbornly slow-witted
- dimwitFoolish, slow person
foolish · not the sharpest tool · thick as a brick · dull · senseless · idiotic · ignorant · sharp as a marble · inexpressive · unintelligent · obtuse · out to lunch · lights are on but nobody's home · halfwit · stupid · knucklehead · dead as a dodo · dunce
dumb as a doornailbrilliant
Intensely bright or gifted
genius · intelligent · clever · brainy · bright
dumb as a doornailsharp as a tack
Extremely intelligent and alert
quick-witted · razor-sharp · keen · quick on the uptake · on the ball
dumb as a doornailsharp as a tack
Extremely intelligent and alert
smart as a whip · bright as a button · quick as a flash · wise as an owl · nobody's fool
door, dumb, doorway, doors, doorstep, doorbell, doorknob, doorman, dumber