beetleheaded
blockheaded
blunt
blunt-witted
chuckleheaded
dim
dim-witted
dopey
dull
dull of mind
dull-headed
dull-pated
dull-witted
fat-witted
fatheaded
gross-headed
heavy
hebetudinous
numskulled
obtuse
slow
slow-witted
sluggish
thick
thick-brained
thick-headed
thick-pated
thick-witted
thickskulled
wooden