84 entries under rational topic. ×

2
deadpan(adjective, set, tough, severe, honest)
2
deliberative(adjective, reasonable, keen, deep)
2
impassive(adjective, calm, tough, restrained)
2
keen(adjective, reasonable, sensible, passionate, deep)
2
museful(adjective, reasonable, keen, deep)
2
realistic(adjective, calm, tough, sensible, dark)
2
reflecting(adjective, reasonable, keen, deep)
2
stolid(adjective, tough, straightforward, sober)
2
unemotional(adjective, straightforward, down-to-earth)
1
abstaining(adjective, calm, sensible, dark, restrained)
1
analytical(adjective, reasonable, keen, deep)
1
apathetic(adjective, tough, straightforward, sober)
1
calculating(adjective, reasonable, keen, deep)
1
cerebral(adjective, reasonable, keen, deep)
1
clear-headed(adjective, calm, sensible, dark, restrained)
1
cold(adjective, calm, close, hard, tough)
1
cold-blooded(adjective, tough, straightforward, sober)
1
down-to-earth(adjective, calm, tough, plain, restrained)
1
dry(adjective, tough, straightforward, temperate)
1
earthy(adjective, tough, straightforward, sober)
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APASmart Define. (2016). serious thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/serious/thesaurus/synonyms
ChicagoSmart Define. 2016. "serious thesaurus" https://smartdefine.org/serious/thesaurus/synonyms (accessed September 25, 2026).
HarvardSmart Define 2016, serious thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/serious/thesaurus/synonyms>.
MLASmart Define. "serious thesaurus" 24 February 2016. Web. 25 September 2026. <https://smartdefine.org/serious/thesaurus/synonyms>