17
energetic(adjective, dull, full, forceful)
11
active(adjective, energetic, fixed, afraid, inoperative)
8
lively(adjective, dull, energetic)
8
busy(adjective, energetic)
7
perky
6
alert(adjective, dull, energetic, careless, indifferent)
6
vigorous(adjective, dull, weak, energetic, powerful)
6
vivacious(adjective, energetic)
5
animated(adjective, energetic, sluggish)
5
vital(adjective, energetic, inactive)
5
business-minded
5
fresh(adjective, inactive)
4
flirty
4
zippy
3
brisk
3
strenuous(adjective, energetic, zealous)
3
curious
3
fast paced
3
sprightly
3
spry(adjective, active, vivacious)
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APASmart Define. (2016). lethargic thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/lethargic/thesaurus/antonyms
ChicagoSmart Define. 2016. "lethargic thesaurus" https://smartdefine.org/lethargic/thesaurus/antonyms (accessed September 24, 2026).
HarvardSmart Define 2016, lethargic thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/lethargic/thesaurus/antonyms>.
MLASmart Define. "lethargic thesaurus" 4 January 2016. Web. 24 September 2026. <https://smartdefine.org/lethargic/thesaurus/antonyms>