half-brained
mentally challenged
half-witted
subnormal
dirtbrain
dense
halfwit
idiot
stupidass
unintelligence
vacancy
not the sharpest tool in the box
not the sharpest knife in the drawer
not the sharpest tool in the shed
stun
underbrained
fool
bonehead
dunce
loggerhead
blockhead
hammerhead
numskull
cerebrally challenged
dunderhead
knucklehead
intellectually challenged
dumbass
muttonhead
fuckhead
shithead
lunkhead
stupid
unintelligent
brainlet
dimwit
vacuous
lackluster
slow
room-temperature IQ
light-witted
dull
simple
simpleton
subintellectual
unbright
subnormality
half-wit
moron
micrencephalous
submoron
imbecile
changeling
retard
cretin
lackbrain
drool bucket
divvie
gormless
acognitive
dumb blonde
short-witted
sophomania
weak
underwitted
simple-mindedly
debutard
nonintelligence
mindless
extramental
vacant
dim
shallow
ungenius
slow on the uptake
nonintelligent
egghead
unskillfulness
underimagined
stewpot
dyscognitive
normal for Norfolk
simple-minded
subexpert
nonintellectual
slow-witted
simple-mindedness
simplicity
pan
few sandwiches short of a picnic
low-mindedness
feeblemindedness
microencephaly