74 entries under serene topic. ×

8
stolid(adjective, calm, quiet, cool, relaxed)
8
tranquil(adjective, feature, state, calm, quiet)
8
unexcitable(adjective, calm, cool, steady, blank)
7
insensible(adjective, cool, temper, cold, indifferent)
7
passionless(adjective, cool, indifferent, detached, blank)
7
phlegmatic(adjective, calm, quiet, cool, relaxed)
7
stoic(adjective, cool, blank, aloof, unemotional)
7
unmoved(adjective, calm, cool, temper, cold)
6
emotionless(adjective, cool, blank, aloof, unemotional)
6
heartless(adjective, cool, indifferent, detached, blank)
6
unfeeling(adjective, calm, cool, relaxed, indifferent)
5
callous(adjective, cool, indifferent, detached, blank)
5
at ease(expression, adjective, calm, relaxed, tranquil)
5
inscrutable(adjective, cool, blank, aloof, unemotional)
5
reserved(adjective, cool, indifferent, blank, aloof)
5
stoical(adjective, calm, cool, indifferent, steady)
4
hardened(adjective, cool, indifferent, blank, aloof)
4
poker-faced(adjective, cool, indifferent, detached, blank)
3
dry(adjective, cool, cold, dead, blank)
3
matter-of-fact(adjective, cool, cold, dead, blank)
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APASmart Define. (2015). nonchalant thesaurus. Retrieved September 29, 2026, from https://smartdefine.org/nonchalant/thesaurus/synonyms
ChicagoSmart Define. 2015. "nonchalant thesaurus" https://smartdefine.org/nonchalant/thesaurus/synonyms (accessed September 29, 2026).
HarvardSmart Define 2015, nonchalant thesaurus, Smart Define, viewed 29 September, 2026, <https://smartdefine.org/nonchalant/thesaurus/synonyms>.
MLASmart Define. "nonchalant thesaurus" 9 December 2015. Web. 29 September 2026. <https://smartdefine.org/nonchalant/thesaurus/synonyms>