unuttered (adj.)
- arcane
- cabalistic
- censored
- classified
- close
- closed
- concealed
- cryptic
- dark
- echoless
- enigmatic
- esoteric
- hermetic
- hidden
- hush-hush
- hushed
- implicit
- inaudible
- latent
- mousy
- mysterious
- noiseless
- occult
- quiescent
- quiet
- restricted
- secret
- silent
- smothered
- soundless
- stifled
- still
- stilly
- suppressed
- tacit
- ulterior
- unarticulated
- undeclared
- understood
- undisclosed
- unexpressed
- unhearable
- unpublished
- unrecorded
- unrevealed
- unsaid
- unsounded
- unspoken
- unsung
- untellable
- untold
- unutterable
- unvoiced
- unwritten
- wordless
