subnormal
idiot
stun
dimwit
dirtbrain
submoron
subnormality
simpleton
halfwit
fool
simple
subintellectual
stupidass
half-witted
mentally challenged
drool bucket
half-brained
birdbrain
nonintellectual
changeling
cretin
retard
half-wit
moron
divvie
imbecile
not the sharpest knife in the drawer
not the sharpest tool in the box
not the sharpest tool in the shed
stupid
lackbrain
dumb genius
unintelligence
muggle
amateur
idiot savant
lackluster
knucklehead
subexpert
dunce
muttonhead
fuckhead
hammerhead
dumbass
cerebrally challenged
room-temperature IQ
dunderhead
intellectually challenged
loggerhead
shithead
bonehead
lunkhead
numskull
unintelligent
blockhead
underbrained
layman
simple-mindedly
dropkick
Muggle
light-witted
monkey
dipshidiot
dense
vacancy
unbright
jack of all trades, master of none
indocible
nondescript
genia
pseudointellectual
rube
mentally deficient person
weak
debutard
sophomania
yokel
hayseed
hick
chawbacon
bumpkin
yahoo
dull
peon
dysrationalia
gormless
normal for Norfolk
maladroit
exceptional
unlearned
hillbilly
bushwhacker