6
energetically(adverb, fast, fully, intensely, fiercely)
6
fixedly(adverb, firm, sharply, solidly, tightly)
6
grimly
6
inflexibly(adverb, strongly, definitely, rigidly, obstinately)
6
powerfully(adverb, fast, fully, intensely, fiercely)
6
stoutly(adverb, fully, quickly, strongly, heavily)
6
sturdily(adverb, fully, powerfully, strongly, greatly)
6
tenaciously(adverb, firm, resolutely, obstinately, stubbornly)
6
vigorously(adverb, fast, fully, intensely, fiercely)
5
unwaveringly
5
unyieldingly(adverb, inelastically)
4
adamantly(adverb, definitely, resolutely, determinedly, obstinately)
4
close(adverb, fast, intensely, fiercely, violently)
4
compactly
4
concretely(adverb, solidly)
4
decidedly
4
definitely(adverb, absolutely, very, really, exactly)
4
determinedly
4
devotedly(absolutely, very, really, exactly, sincerely)
4
durably(adverb, severely, strongly, definitely, strictly)
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APASmart Define. (2015). firmly thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/firmly/thesaurus/synonyms
ChicagoSmart Define. 2015. "firmly thesaurus" https://smartdefine.org/firmly/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, firmly thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/firmly/thesaurus/synonyms>.
MLASmart Define. "firmly thesaurus" 14 April 2015. Web. 22 September 2026. <https://smartdefine.org/firmly/thesaurus/synonyms>