80 entries under reasonable topic. ×

4
engrossed(adjective, keen, deep, rational)
4
sober(adjective, sound, keen, sensible)
4
sound(adjective, sensible, reasoning, intellectual)
3
attentive(adjective, keen, deep, rational)
3
brainy(adjective, keen, smart, bright)
3
deductive(adjective, sound, sensible, reasoning)
3
knowing(noun, adjective, understanding, sound)
3
melancholy(adjective, keen, deep, rational)
3
museful(adjective, keen, thought, deep)
3
plausible(adjective, reasoning, intellectual, mental)
3
prudent(sound, sensible, reasoning, intellectual)
3
ratiocinative(adjective, sound, sensible, reasoning)
3
sane(adjective, sound, sensible, reasoning)
3
studious(adjective, keen, thought, deep)
3
wistful(adjective, keen, thought, deep)
2
circumspect(sound, sensible, reasoning, intellectual)
2
cogent
2
cognitive(sound, sensible, reasoning, intellectual)
2
enlightened(sound, smart, bright, sensible)
2
judicious(adjective, sound, sensible, reasoning)
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APASmart Define. (2016). thinking thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/thinking/thesaurus/synonyms
ChicagoSmart Define. 2016. "thinking thesaurus" https://smartdefine.org/thinking/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2016, thinking thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/thinking/thesaurus/synonyms>.
MLASmart Define. "thinking thesaurus" 11 February 2016. Web. 22 September 2026. <https://smartdefine.org/thinking/thesaurus/synonyms>