41
dull(adjective, calm, quiet, set, hard)
33
level(noun, verb, adjective, adverb, quiet)
31
even(verb, adjective, adverb, calm, quiet)
31
insipid(adjective, characteristic, dull, hard, weak)
30
boring(adjective, dull, quiet, weak, simple)
27
vapid(adjective, characteristic, dull, set, weak)
27
smooth(verb, adjective, calm, weak, kind)
27
stale(adjective, characteristic, dull, set, hard)
26
dead(adjective, adverb, characteristic, dull, quiet)
26
bland(adjective, dull, quiet, weak, kind)
26
tedious(adjective, dull, weak, simple, plain)
25
apartment(noun, place, house, home, building)
23
plane(noun, verb, adjective, calm, quiet)
23
jejune(noun, adjective, dull, set, weak)
23
lifeless(adjective, calm, dull, quiet, weak)
23
monotonous(adjective, dull, quiet, weak, simple)
23
tiresome(adjective, dull, stupid, ordinary, dry)
23
uninteresting(adjective, dull, weak, nasty, plain)
20
prosaic(adjective, dull, set, weak, simple)
19
plain(noun, adjective, calm, dull, quiet)
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APASmart Define. (2016). flat thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/flat/thesaurus/synonyms
ChicagoSmart Define. 2016. "flat thesaurus" https://smartdefine.org/flat/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2016, flat thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/flat/thesaurus/synonyms>.
MLASmart Define. "flat thesaurus" 1 March 2016. Web. 20 September 2026. <https://smartdefine.org/flat/thesaurus/synonyms>