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