97 entries under thoughtful topic. ×

2
attentive(adjective, reasonable, keen, deep)
2
brooding(adjective, sober, thinking, grave)
2
deadpan(adjective, set, tough, severe, honest)
2
erudite(deep, cultured, reflective)
2
intellectual(adjective, reasonable, keen, deep)
2
pondering(adjective, reasonable, keen, deep)
2
preoccupied(adjective, reasonable, keen, deep)
2
recondite(intense, heavy, deep, fierce)
2
reflecting(adjective, reasonable, keen, deep, rational)
2
ruminating(thinking, meditative)
2
sage(deep, grand, esteemed, reflective)
2
scholarly(deep, cultured, reflective)
2
shrewd(deep, reflective)
2
speculative(bad, heavy, thinking, risky)
2
thinking(adjective, reasonable, keen, deep)
1
absorbed(adjective, reasonable, keen, deep)
1
brainy(adjective, reasonable, keen, sensible, deep)
1
cold sober(expression, adjective, calm, set, cool)
1
discerning(adjective, reasonable, keen, sensible, heavy)
1
eager(adjective, keen, warm, intense, passionate)
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APASmart Define. (2016). serious thesaurus. Retrieved September 28, 2026, from https://smartdefine.org/serious/thesaurus/synonyms
ChicagoSmart Define. 2016. "serious thesaurus" https://smartdefine.org/serious/thesaurus/synonyms (accessed September 28, 2026).
HarvardSmart Define 2016, serious thesaurus, Smart Define, viewed 28 September, 2026, <https://smartdefine.org/serious/thesaurus/synonyms>.
MLASmart Define. "serious thesaurus" 24 February 2016. Web. 28 September 2026. <https://smartdefine.org/serious/thesaurus/synonyms>