4
vitality(noun, force, quality, drive, character)
4
warmth(noun, force, quality, character, strength)
3
bias
3
bosom(noun, emotion, mood, temperament, core)
3
bottom
3
brass(noun, spirit, courage, liveliness, guts)
3
diathesis
3
elan(noun, force, quality, power, character)
3
essence(noun, force, quality, character, strength)
3
force(noun, quality, character, strength, spirit)
3
gist(noun, emotion, mood, temperament, core)
3
gusto(noun, emotion, mood, temperament, core)
3
gut(noun, quality, slang, fear)
3
hardiness(noun, spirit, courage, liveliness, daring)
3
humor(noun, nature, force, quality, kind)
3
inclination(noun, nature, quality, character, emotion)
3
indomitability(noun, strength, spirit, determination, courage)
3
kidney(noun, strength, spirit, determination, courage)
3
liveliness(noun, force, quality, character, strength)
3
marrow(noun, emotion, mood, temperament, core)
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APASmart Define. (2015). mettle thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/mettle/thesaurus/synonyms
ChicagoSmart Define. 2015. "mettle thesaurus" https://smartdefine.org/mettle/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, mettle thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/mettle/thesaurus/synonyms>.
MLASmart Define. "mettle thesaurus" 10 April 2015. Web. 22 September 2026. <https://smartdefine.org/mettle/thesaurus/synonyms>