50 entries under fast topic. ×

2
actively(adverb, sprightly, severely, seriously)
2
boisterously(adverb, sprightly, severely, seriously)
2
earnestly(adverb, seriously, intensely, heartily)
2
forcibly(adverb, sprightly, severely, intensely)
2
keenly(adverb, sprightly, severely, seriously)
2
meanly(adverb, sprightly, severely, seriously)
2
remorselessly(adverb, intensely, violently, powerfully)
2
rigorously(adverb, sprightly, severely, seriously)
2
roughly(adverb, sprightly, severely, intensely)
2
spiritedly(adverb, seriously, intensely, earnestly)
2
stormily(adjective, adverb, sprightly, severely)
2
uproariously(adverb, sprightly, severely, seriously)
1
animatedly(adverb, sprightly, seriously, intensely)
1
briskly(adverb, sprightly, seriously, intensely)
1
heavily(adverb, sprightly, severely, seriously)
1
like fury(expression, adverb, sprightly, severely)
1
painfully(adverb, sprightly, severely, seriously)
1
powerfully(adverb, sprightly, severely, seriously)
1
rowdily(adverb, sprightly, severely, seriously)
1
seriously(adverb, severely, intensely, vigorously)
10 years ago|9.1k views|share |citing 
APASmart Define. (2016). fiercely thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/fiercely/thesaurus/synonyms
ChicagoSmart Define. 2016. "fiercely thesaurus" https://smartdefine.org/fiercely/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2016, fiercely thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/fiercely/thesaurus/synonyms>.
MLASmart Define. "fiercely thesaurus" 24 March 2016. Web. 23 September 2026. <https://smartdefine.org/fiercely/thesaurus/synonyms>