simpleminded
dumbassed
numbskulled
bodoh
blockheadish
stupidy
dym
thick
bull
dumb as an ox
retardical
numbnut
dumbbutt
one brick short of a full load
lamebrained
boofheaded
thickwitted
opaque
muddlebrained
goofy ahh
dumb as nails
dumbass
dunderheaded
stupidass
thick as mince
dumb like a fox
stupidish
dumb as a bag of hammers
pratty
bubbleheaded
baka
fuckheaded
duuumb
dopey
thick as pig shit
fool
goosish
retarded
dumb as a stump
pillocky
shit-for-brains
thick as a whale omelette
dumb
dumber than a rock
dumb as a post
dumb as dirt
rock-dumb
twp
soft
dumb as a doorknob
dumb as a box of rocks
dumber than a box of rocks