12
inert(adjective, dull, quiet, weak, moving)
12
insouciant(adjective, dull, indifferent, unsympathetic, sluggish)
12
uninterested(adjective, dull, cool, weak, easy)
11
inactive(adjective, dull, quiet, weak, easy)
11
languorous(adjective, dull, weak, easy, slow)
11
lifeless(adjective, calm, quiet, tough, slow)
11
lukewarm(adjective, dull, cool, indifferent, restrained)
10
calm(adjective, quiet, cool, tough, relaxed)
10
confident
10
slothful(adjective, dull, quiet, easy, slow)
9
composed(adjective, calm, quiet, cool, still)
9
dispassionate(adjective, calm, quiet, cool, relaxed)
9
imperturbable(adjective, calm, quiet, cool, relaxed)
9
self-possessed(adjective, calm, quiet, relaxed, still)
9
serene(adjective, calm, quiet, cool, relaxed)
9
uncaring(adjective, indifferent, detached, unfriendly, distant)
9
unmoved(adjective, calm, cool, indifferent, detached)
9
unresponsive(adjective, calm, dull, cool, slow)
8
unenthusiastic(adjective, dull, cool, weak, easy)
7
detached(adjective, calm, quiet, cool, relaxed)
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APASmart Define. (2015). phlegmatic thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/phlegmatic/thesaurus/synonyms
ChicagoSmart Define. 2015. "phlegmatic thesaurus" https://smartdefine.org/phlegmatic/thesaurus/synonyms (accessed September 25, 2026).
HarvardSmart Define 2015, phlegmatic thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/phlegmatic/thesaurus/synonyms>.
MLASmart Define. "phlegmatic thesaurus" 10 April 2015. Web. 25 September 2026. <https://smartdefine.org/phlegmatic/thesaurus/synonyms>