7
shiftless(adjective, dull, careless, sluggish, dubious)
7
slack off(verb, expression, stop, delay, rest)
7
supine(adjective, dull, loose, idle, sluggish)
6
apathetic(noun, adjective, dull, quiet, easy)
6
dormant(adjective, dull, still, sluggish, lazy)
6
down(adjective, dull, increase, weak, low)
6
drooping(adjective, weak, soft, loose, lifeless)
6
easygoing(adjective, soft, tolerant, lifeless, lenient)
6
falloff
6
forgetful(adjective, soft, careless, indifferent, remember)
6
goldbrick(verb, slip, avoid, quit, relax)
6
indifferent(noun, adjective, dull, quiet, soft)
6
informal(adjective, free, out, unrestricted, released)
6
leeway(noun, excess, looseness)
6
lifeless(adjective, dull, quiet, flat, slow)
6
play(noun, excess, looseness)
6
sagging(adjective, weak, soft, loose, lifeless)
6
slackness
6
slipshod(adjective, weak, soft, careless, loose)
6
slump
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APASmart Define. (2016). slack thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/slack/thesaurus/synonyms
ChicagoSmart Define. 2016. "slack thesaurus" https://smartdefine.org/slack/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2016, slack thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/slack/thesaurus/synonyms>.
MLASmart Define. "slack thesaurus" 26 February 2016. Web. 21 September 2026. <https://smartdefine.org/slack/thesaurus/synonyms>