147 entries under dull topic. ×

9
tardy(adjective, slow, sluggish, late)
8
laggard(noun, adjective, quiet, easy)
8
passive(adjective, careless, loose, sluggish)
8
quiet(verb, adjective, calm, smooth)
8
torpid(adjective, quiet, flat, slow)
7
heavy(adjective, quiet, moderate, easy)
7
lackadaisical(adjective, slow, sluggish, lazy)
7
off(adjective, increase, moderate, low)
7
shiftless(adjective, careless, sluggish, dubious)
7
supine(adjective, loose, idle, sluggish)
6
apathetic(noun, adjective, quiet, easy)
6
dormant(adjective, still, sluggish, lazy)
6
down(adjective, increase, weak, low)
6
indifferent(noun, adjective, quiet, soft)
6
lifeless(adjective, quiet, flat, slow)
5
backward(adjective, low, slow, late)
5
dead(quiet, flat, still, lifeless)
5
gradual(late, slowness, behind)
5
slow-moving(adjective, quiet, easy, slow)
5
stagnant(adjective, quiet, moderate, flat)
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APASmart Define. (2016). slack thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/slack/thesaurus/synonyms
ChicagoSmart Define. 2016. "slack thesaurus" https://smartdefine.org/slack/thesaurus/synonyms (accessed September 25, 2026).
HarvardSmart Define 2016, slack thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/slack/thesaurus/synonyms>.
MLASmart Define. "slack thesaurus" 26 February 2016. Web. 25 September 2026. <https://smartdefine.org/slack/thesaurus/synonyms>