1 cylinder mind.
12 shy of a dozen.
A bad spot on the disk.
A bungalow (got nothing upstairs)
A couple of cans short of six-pack.
A couple of chips short of a full motherboard.
A couple of open splices.
A couple of sandwiches short of a picnic.
A few bits shy of a word.
A few clowns short of a circus.
A few feathers short of a whole duck.
A few fries short of a Happy Meal.
A few peas short of a casserole.
A little light in his/her loafers.
A loose chip on the micro processor.
A quart low.
About as bright as an LED.
About as sharp as a bowl of jello.
About as sharp as a bowling ball.
About as sharp as a sack of wet leather.
About fifteen cents short.
About three cents short of a dollar.
Air between the ears.
All booster - no payload.
All crown - no filling.
All foam, no beer.
All his/her eggs in the same basket.
All his/her marbles in one bag.
All the lights are on but there's nobody home.
All the lights don't shine in his/her marquis
An experiment in Artificial Stupidity.
An intellect rivaled only by garden tools.
As smart as bait.
As thick as two short planks.
Attic's a little dusty.
Back burners not fully operating.
Bad spot on the disk.
Banking at 9 a.m. (not meaningful since advent of ATMs)
Bats in the belfry.
Been playing with his/her wand too much.
Body by Fisher, brains by Mattel
Braindamaged (courtesy of Bill Cosby, Himself).
Braindead.
CPU not connected to the bus.
Car's only got three wheels, and one's going flat.
Couldn't pour water out of a boot with instructions on the heel.
Crazy as a loon.
Crazy as all get out.
Doesn't have all his/her cornflakes in one box.
Doesn't have all his/her dogs barking.
Doesn't have all his/her dogs on one leash.
Doesn't have all of his/her groceries in the same bag.
Doesn't have all the dots on his/her dice.
Doesn't have both oars in the water.
Doesn't know if his/her biscuits (bread) are (is) all done.
Doesn't know much, but leads the league in nostril hair.
Doesn't know which side of the toast the butter is on.
Don't have all your dogs barking.
Driving with two wheels in the sand.
Dumb as a box of rocks.
Echoes between the ears.
Elevator doesn't go all the way to the top floor.
Forgot to pay his/her brain bill.
Got a few tiles missing from his/her Space Shuttle.
Got a screw loose.
Got one boot stuck in the sand.
Got the mental agility of a soap dish.
Had a head crash.
Half a quart low.
Has a few screws loose.
Has a mind like a sieve.
Has a room temperature IQ.
Has an I.Q. of 2, but it takes 3 to grunt.
Has bats in his/her belfry.
Hasn't got all his/her china in the cupboard.
Hasn't got enough sense to come in out of the rain.
Hasn't got enough sense to stay out in the rain. ('60s flower child)
He ain't wrapped too tight.
He doesn't have both oars in the water.
He fell out of the stupid tree and hit every branch on the way down.
He has both oars in the water, but on the same side of the boat!
He has signs on both ears saying Space for Rent.
He has two brains. One is lost and the other is out looking for it.
He is only hitting on 7 cylinders.
He is playing hockey with a warped puck.
He isn't playing with a full deck.
He left the store without all of his/her groceries.
He lost his/her trollies.
He parked his/her head and forgot where he left it.
He's a few bricks short of a full load.
He's a couple of bricks short of a hod.
He's a couple of volts below threshold
He's about a half a bubble off plumb.
He's dumber than a red brick.
He's flying on one engine.
He's got a few wait states.
He's got a mind like a steel trap - anything entering gets crushed and mangled
He's got a mind like a steel trap -- full of mice.
He's got a mind like a steel trap -- rusty and stuck closed.
He's got the attention span of an overripe grapefruit.
He's not digging in the same ditch with the rest of us!
He's not running on full thrusters.
He's paged-out.
He's reading off a empty disk.
He's running at 400 baud.
He's swapped out.
He's working with an unformatted disk.
his/her antenna doesn't pick up all the channels.
his/her belt doesn't go through all the loops.
his/her chimney's clogged.
his/her elevator is stuck between floors.
his/her little red choo choo done jumped the track.
his/her receiver is off the hook.
his/her skylight leaks a little.
his/her dialing thumb must be broken.
his/her reset line is glitching.
How 'bout There's no wind in the windmills of his/her mind.
How about The porch light is on, but there's nobody home.
If (his/her) IQ was 2 points higher (he/she) would be a rock.
If brains were dynamite he/she couldn't blow his/her hat off.
If brains were dynamite, he/she wouldn't have enough to blow his/her nose.
If he had another brain cell, it would be lonely.
If he were any more stupid, he would have to be watered twice a week.
In a world of Hard Disks, he/she is using a 1S-2D floppy for brains.
In the shopping mall of the mind, he's in the toy department.
Isn't playing with a full deck.
It would be easier to count the bricks left than the bricks missing!
Judging by the old saying, "What you don't know can't hurt you", s/he's practically invulnerable.
Leads 3 & 4 (RS-232) permanently connected to ground.
Light not buring too bright.
Looney tunes.
Loony as a jay bird.
Loose wire to headset/ringer.
Lugnuts rattling in the hubcaps.
Mainspring's wound too tight.
Missing a few catalogue cards.
Missing a few gears.
Missing a few marbles.
Mouth is in gear, brain is in neutral.
Nice house not much furniture.
Nice house, but nobody home.
Nice house, nobody home.
No grain in the silo.
No one at the throttle.
Not firing on all thrusters.
Not firing on all cylinders.
Not playing with a full deck.
Not playing with a full deck? hell he's not even in the game!
Not too tightly wrapped.
Nothing between the stethoscopes.
Nutty as a fruitcake.
Off his/her rocker.
Off your rocker.
Oil doesn't reach his/her dipstick.
On the batting end of a no-hitter.
One brick shy of a load.
One Fruit Loop short of a full bowl.
One shingle shy a roof.
One taco short of a combination plate.
Only got one oar in the water.
Only operating at about half a watt.
Only playing with the jokers.
Over the Rainbow.
Paddling with one oar.
Paralyzed from the neck up.
Pin 8 is floating.
Playing hockey with a warped puck.
Proof that evolution can go in reverse.
Raw cookie dough.
Renewable energy source for hot air balloons.
Riding a tippy canoe.
Running on empty.
Sailboat fuel for brains.
Sending back packets, but the checksums are wrong.
Several nuts short of a full pouch.
Sharp as a bowling ball.
She was minus so many buttons ...
Short a few cards.
Six shy of a dozen.
Skating on the wrong side of the ice.
Some bugs in his/her software.
Some drink form the fountain of knowledge, but he just gargled.
Somebody else is doing the driving for that boy!
Someone blew out his/her pilot light.
Surfing in Nebraska.
Teflon brain (nothing sticks).
The best part of you ran down your mother's legs. (Jackie Gleason)
The brains of a house plant
The caboose seems to be pulling the engine.
The carnival has closed.
The cheese has slid off his/her cracker.
The gates are down, the lights are flashing, but the train isn't coming.
The going got weird and he turned pro.
The smoke doesn't make it to the top of his/her chimney.
The synapses are about that far apart.
The wheel's still turning, but the hamster's dead.
There's a leak in his/her ceiling.
Thick as a brick.
Too much yardage between the goalposts
Toys in the attic.
Tuppence short of a shilling, or Not a full shilling.
Two bits shy of a word.
Vacancy on the top floor.
Warning: Objects in mirror are dumber than they appear.
Was hiding behind the door when they passed out brains.
Was napping in the nut pile the day that God was cracking nuts.
Welcome light on, but no-one home.
When he plays poker, it's hard to tell whether he has an ace up his/her sleeve or if the ace is missing from his/her deck altogether.
You can hear the wind whistling through his/her ears.
You probably like to do everything the hard way... like making love while standing up in a hammock.
Your clock doesn't have all its numbers.
Your little red choo-choo's gone chugging 'round the bend.
