4
opaque
3
dull
2
doltish
2
slow
2
thickheaded
2
unintelligent
1
backward
1
birdbrained
1
blockheaded
1
blunderheaded
1
brain-dead
1
bubbleheaded
1
cloddish
1
dense
1
dorky
1
dumb
1
empty-headed
1
fatuous
1
gormless
1
half-witted
<12>
11 years ago|5.7k views|share |citing 
APASmart Define. (2015). dunderheaded thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/dunderheaded/thesaurus/synonyms
ChicagoSmart Define. 2015. "dunderheaded thesaurus" https://smartdefine.org/dunderheaded/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2015, dunderheaded thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/dunderheaded/thesaurus/synonyms>.
MLASmart Define. "dunderheaded thesaurus" 14 April 2015. Web. 20 September 2026. <https://smartdefine.org/dunderheaded/thesaurus/synonyms>