4
oafish(adjective, dull, simple, slow, stupid)
4
reticent(adjective, close, quiet, soft, low)
4
ridiculous(adjective, foolish, impractical, unintelligent, half-baked)
4
wacky
3
opaque(adjective, dull, silly, foolish, stupid)
3
soundless(adjective, close, quiet, soft, low)
3
addle-pated
3
beaglebrained(adjective, stupid)
3
bleak
3
closemouthed(quiet, soft, still, reticent, silent)
3
cretinous(adjective, foolish)
3
cushion-witted(adjective, stupid)
3
dimmed
3
empty(adjective, ineffective, fruitless)
3
fat(adjective, silly, stupid, green, thick)
3
halfwitted
3
inaudible(adjective, close, quiet, soft, low)
3
inert(adjective, dull, heavy, stupid, impassive)
3
insensate(adjective, dull, simple, slow, informal)
3
irrational
10 years ago|23k views|share |citing 
APASmart Define. (2016). dumb thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/dumb/thesaurus/synonyms
ChicagoSmart Define. 2016. "dumb thesaurus" https://smartdefine.org/dumb/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2016, dumb thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/dumb/thesaurus/synonyms>.
MLASmart Define. "dumb thesaurus" 29 March 2016. Web. 23 September 2026. <https://smartdefine.org/dumb/thesaurus/synonyms>