unbright
slow-witted
lackluster
dull
half-witted
shallow
underwitted
vacancy
dim
nonsavvy
unsophisticated
unvalorous
unimpressible
mentally challenged
short-witted
light-witted
unsmart
imaginationless
gormless
simple-mindedly
cloistered
halfwit
not the sharpest knife in the drawer
not the sharpest tool in the box
not the sharpest tool in the shed
nonintelligent
unintelligent
qualitiless
untalented
dullness
naïveté
subdued
simpleminded
soft
stupidass
incurious
mindless
vacant
unperceiving
vacuous
idiot
subnormal
simpleton
indocible
nonintellectual
extramental
simplicity
unintelligence
nondescript
insensibility