1
speechless(adjective, close, quiet, soft, obscure)
1
stifled
1
still as death(expression, idiom)
1
stilled(adjective, close, quiet, soft, low)
1
stilly
1
subaudible
1
suppressed
1
taciturn(adjective, close, quiet, soft, low)
1
tight-lipped(adjective, close, quiet, soft, low)
1
top-secret
1
top secret
1
ulterior
1
unarticulated
1
unbreatheable
1
uncommunicative(adjective, close, quiet, soft, low)
1
under security
1
under wraps
1
undisclosable
1
undisclosed
1
undivulgable
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APASmart Define. (2015). unuttered thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/unuttered/thesaurus/synonyms
ChicagoSmart Define. 2015. "unuttered thesaurus" https://smartdefine.org/unuttered/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, unuttered thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/unuttered/thesaurus/synonyms>.
MLASmart Define. "unuttered thesaurus" 14 April 2015. Web. 23 September 2026. <https://smartdefine.org/unuttered/thesaurus/synonyms>