126 entries under sober topic. ×

8
ruminative(adjective, reasonable, rational, thoughtful)
8
somber(adjective, calm, dull, cool, severe)
7
pensive(adjective, set, keen, unhappy, gloomy)
7
austere(adjective, set, strong, hard, tough)
6
deliberate(adjective, calm, set, cool, severe)
6
demure(adjective, calm, cool, modest, shy)
6
reflective(adjective, set, deep, thoughtful)
6
resolved(adjective, severe, firm, harsh, cruel)
5
calm(adjective, cool, tough, sensible, relaxed)
5
funereal(adjective, dull, dark, gloomy)
4
contemplative(adjective, reasonable, thoughtful, thinking)
4
collected(adjective, calm, cool, dark, relaxed)
4
cool(adjective, calm, sensible, unusual, relaxed)
4
firm(adjective, strong, hard, tough, severe)
4
set(adjective, strong, severe, firm, thoughtful)
3
cogitative(adjective, reasonable, keen, deep, thoughtful)
3
dull(adjective, tough, severe, dark, gloomy)
3
lugubrious(adjective, dull, dark, gloomy, melancholy)
3
musing(adjective, reasonable, keen, deep, thoughtful)
3
practical(adjective, calm, tough, plain, dark)
10 years ago|45k views|share |citing 
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>