stupidy
bodoh
blockheadish
simpleminded
numbskulled
dumbassed
bull
dumb as an ox
numbnut
dumbbutt
thick
retardical
one brick short of a full load
dumbfuckery
stupidicy
foppery
pratty
opaque
dopey
stupidass
thick as mince
baka
thickhead
bee-brained
dym
fatheadedly
stockishly
dumb as a stump
shtus
thick as pig shit
retarded
fatuitous
rock-dumb
thick as a whale omelette
pillocky
dumber than a rock
dumb as dirt
dumb
shit-for-brains
dumb as a post
sohai
dumbish
flea-brained
dunderheaded
dumbass
chuckleheaded
muddlebrained
lamebrained
brain damage
thickheadedness
dumb as a bag of hammers
dunderheadedness
numskullery
dunderheadism
stockishness
sawney
sill
fuckwittedness
retardation
goofball
tomfool
dumb as nails
anserous
tardish
lackwitted
cockamamy
peabrained
dumb as a doorknob
airheaded
dumber than a box of rocks
thick as two short planks
thick as a plank
dumb as a box of rocks
goosish
fool
soft
twp
doinky
anserine
crackbrained
ninnyish
tomfoolish
boobery
malarkey
goosy
twonk
load
thickwitted
who shot John
stuuupid
dipshittery
nut-head
stupidish
bubbleheaded
dumb like a fox
bollocks more like
idiocity
idioticy
stupidly