layman
ungenteelness
unexploredness
unconfinedness
uninterestedness
unsurpassableness
jackleg
undertalented
naïveté
unpracticality
unappealingness
unmeekness
unvaryingness
untraceableness
undelightfulness
undisputatiousness
unbegottenness
vapidity
vapidness
tameness
untenantableness
unbefittingness
uncivilizedness
jejunity
unprovableness
jejuneness
uninspiredness
learningless
weak
unadventuresomeness
unappeasableness
ungainfulness
unquiescence
unimposingness
untenantability
amateur
stultified
not the sharpest tool in the box
unmeritoriousness
not the sharpest tool in the shed
untrendiness
not the sharpest knife in the drawer
unlikability
uncomprehendingness
unuprightness
unbenignity