dumb as a doorknob
Lacking all sense
Dumb as a doorknob describes someone extremely stupid or slow-witted.
The comparison works because doorknobs are inanimate objects incapable of thought—and the alliteration makes it memorable.
He's dumb as a doorknob, but at least he's honest.
Sometimes varied to *dumb as a box of rocks* or *dumb as a post*.
- unintelligentLacking cognitive ability
- foolishLacking good sense
- obtuseLacking mental sharpness
- simplemindedLacking mental acuity
- slow-wittedLacking mental quickness
witless · vacuous · dense · stupid · ignorant · not the sharpest tool in the shed · brain like a sieve · lights are on but nobody's home · dim-witted · thick as a brick · sharp as a marble · moronic · doorknob · deadhead · brick · dull · numskull · rock
dumb as a doorknobbrilliant
Intensely bright or gifted
genius · smart as a whip · sharp as a tack · intelligent · clever
dumb as a doorknobsharp as a tack
Extremely intelligent and alert
smart as a whip · bright as a button · wise as an owl · nobody's fool
dumb as a doorknobwhiz kid
Exceptionally talented youngster
wunderkind · prodigy · mastermind · brainiac · egghead
dumb, dumber, dumbest, dumbly, dumbness, dumbed, dumbing, door, doors