subexpert
outskilled
subintellectual
worse
underachiever
inadequacy
dense
slow on the uptake
ham-fisted
skillessness
subnormal
unproficiency
improficiency
dequalification
nonproficiency
incompetent
fumbling
bungling
inexpertness
clumsy
mentally challenged
ungenius
incompetence
dim
underskilled
obtuse
light-witted
unsmart
dull
dumb
slow
not the sharpest knife in the drawer
not the sharpest tool in the box
not the sharpest tool in the shed
indocible
lackluster
submoron
idiot
half-witted
stupid
amateur
inexpert
amateurish
unskilled
unadept
vacancy
normal for Norfolk
unworldly
insufficiency
inexpertise