12
second-nature(adjective, inside, instinctive, interior, automatic)
12
straightforward(adjective, open, direct, free, simple)
12
unthinking(adjective, instinctive, gut, automatic, intuitive)
11
frank(adjective, open, free, simple, easy)
11
constitutional(adjective, start, complete, basic, instinctive)
11
informal(adjective, adverb, calm, open, smooth)
11
unpremeditated(adjective, impulse, instinctive, automatic, involuntary)
11
unpretentious(adjective, calm, open, smooth, simple)
10
casual(adjective, adverb, calm, open, smooth)
10
characteristic(adjective, simple, common, ordinary, familiar)
10
innocent(adjective, open, smooth, simple, friendly)
10
unfeigned(adjective, open, correct, right, honest)
10
unlearned(adjective, simple, crude, ignorant, unsophisticated)
10
unstudied(adjective, open, simple, reasonable, clean)
9
authentic(adjective, simple, correct, right, bright)
9
conventional(adjective, characteristic, simple, pure, common)
9
deep-seated(adjective, characteristic, essential, basic, instinctive)
9
easygoing(adjective, calm, simple, plain, informal)
9
everyday(adjective, characteristic, simple, informal, pure)
9
faithful(adjective, open, honest, true, straightforward)
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APASmart Define. (2016). natural thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/natural/thesaurus/synonyms
ChicagoSmart Define. 2016. "natural thesaurus" https://smartdefine.org/natural/thesaurus/synonyms (accessed September 25, 2026).
HarvardSmart Define 2016, natural thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/natural/thesaurus/synonyms>.
MLASmart Define. "natural thesaurus" 15 February 2016. Web. 25 September 2026. <https://smartdefine.org/natural/thesaurus/synonyms>