dull-minded
lunky
shitbrained
dull-witted
fuckheaded
doltish
brainless
rube
sheep-headed
airhead
sottish
melon-headed
lackwit
Boeotian
dumbling
thickwitted
mullet-headed
shonky
addlehead
addle-brain
dull
shit for brains
blinkard
punk-ass
underwitted
blockish
Benny
dumb as a doornail
unwitty
dunny
chowderheaded
gowl
slimy
beefheaded
boofheaded
short-witted
schmendrick
raffish
meathead
dropkick
dull-headed
snide
kooky
slack-jawed
unintelligently
gay-ass
phony as a three-dollar bill
muddle-headed
gawk
lunkheaded
boobyish
pillock
wiliness
roguish
dim-witted
idiotlike
batchy
imbecilic
jerk
blonde
frontal lobeless
inaniloquent
mouth breather
drool bucket
beigist
dimwittedly
cock
gaby
uncleverly
ungallant
overexact
thickheaded
clodpated
gonk
half-witted
divvie
addle
blah
obtuse
doilem
lackbrain
nitty
mad
muff
lackadaisical
dickheaded
dim bulb
hard as nails
git
goofy ahh
dim-bulb
mammet
unprepossessing
asshat
twang
on the nose
pachycephalic
one fry short of a Happy Meal
cerebrally challenged