5
veritably(adverb, really, seriously, truly, honestly)
4
plainly(adverb, style, manner, sincerity, artlessly)
4
dearly(adverb, style, manner, sincerity)
4
reliably(adverb, really, seriously, truly, honestly)
4
truely(adverb, style, manner, sincerity)
4
trustworthily(adverb, style, manner, sincerity, truthfully)
4
whole-souledly(adverb, style, manner, sincerity)
4
without a doubt(expression, adverb, really, seriously, truly)
4
zestfully(adverb, style, pleasure, manner, sincerity)
3
openly(adverb, style, manner, sincerity, artlessly)
3
directly(adverb, style, manner, sincerity, artlessly)
3
substantially(adverb, style, manner, sincerity)
3
as a matter of fact(expression, adverb, really, seriously, truly)
3
ethically(adverb, style, manner, sincerity, truthfully)
3
for fair(expression, adverb, really, seriously, truly)
3
in all honesty(expression, adverb, style, manner, sincerity)
3
in effect(expression, adverb, really, seriously, truly)
3
in point of fact(expression, adverb, really, seriously, truly)
3
kind regards(expression, idiom, respect, faith, sincerity)
3
kindheartedly(adverb, style, manner, sincerity, with enthusiasm)
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APASmart Define. (2016). sincerely thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/sincerely/thesaurus/synonyms
ChicagoSmart Define. 2016. "sincerely thesaurus" https://smartdefine.org/sincerely/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2016, sincerely thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/sincerely/thesaurus/synonyms>.
MLASmart Define. "sincerely thesaurus" 30 March 2016. Web. 23 September 2026. <https://smartdefine.org/sincerely/thesaurus/synonyms>