84 entries under rational topic. ×

1
emotionless(adjective, tough, straightforward, sober)
1
engrossed(adjective, reasonable, keen, deep)
1
factual(adjective, tough, straightforward, sober)
1
farsighted(adjective, reasonable, keen, deep)
1
feasible(adjective, tough, straightforward, sober)
1
flat(adjective, tough, straightforward, sober)
1
hard-boiled(adjective, calm, strong, hard, tough)
1
hardheaded(adjective, strong, hard, tough, severe)
1
impersonal(adjective, tough, straightforward, sober)
1
inhibited(adjective, calm, sensible, dark, restrained)
1
levelheaded(adjective, calm, reasonable, sensible, dark)
1
lifeless(adjective, tough, straightforward, sober)
1
matter-of-fact(adjective, straightforward, practical, realistic)
1
mundane(adjective, tough, straightforward, sober)
1
naked(adjective, tough, straightforward, sober)
1
objective(adjective, tough, straightforward, sober)
1
philosophic(adjective, reasonable, keen, deep)
1
phlegmatic(adjective, tough, straightforward, sober)
1
plain(adjective, calm, open, tough, honest)
1
pragmatic(adjective, tough, straightforward, sober)
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APASmart Define. (2016). serious thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/serious/thesaurus/synonyms
ChicagoSmart Define. 2016. "serious thesaurus" https://smartdefine.org/serious/thesaurus/synonyms (accessed September 26, 2026).
HarvardSmart Define 2016, serious thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/serious/thesaurus/synonyms>.
MLASmart Define. "serious thesaurus" 24 February 2016. Web. 26 September 2026. <https://smartdefine.org/serious/thesaurus/synonyms>