unsounded

Depths not plumbed

Unsounded describes something not measured or explored—especially depths.

Waters that are unsounded haven't been plumbed; feelings that are unsounded haven't been examined: the unsounded depths of grief.

Separately, unsounded can mean not pronounced: The k in "knife" is unsounded.

silent

noiseless

Producing no sound

quietLacking in sound
hushedReduced to silence
stillUnmoving, or continuing

inaudible · mute · unheard · voiceless · speechless · calm · peaceful · tranquil · serene · muffled

unfathomed

unplumbed

Not yet measured for depth

unmeasuredNot quantified or gauged
unexploredNot yet investigated
unchartedNot yet documented

unknown · fathomless · depthless · bottomless · abyssal · deep · profound · immeasurable · unprobed · unsurveyed

unspoken

tacit

Understood without words

implicitUnderstood without being stated
unstatedNot openly expressed
unexpressedNot communicated outwardly

unvoiced · unuttered · latent · understood · assumed · presupposed · unmentioned · undeclared · unarticulated · wordless

mysterious

enigmatic

Puzzling and obscure

crypticObscure in meaning
inscrutableImpossible to understand
arcaneUnderstood by few

obscure · hidden · veiled · secret · occult · esoteric · unknowable · impenetrable · unfathomable · opaque

Opposites

audibility

unsoundedaudible

Capable of being detected by ear

sounded · pronounced · heard · hearable · vocalized

depth measurement

unsoundedsounded

Produced audible vibration

fathomed · measured · charted · plumbed · surveyed

vocalization/pronunciation

unsoundedpronounced

Spoken aloud formally

sounded · voiced · articulated · spoken · enunciated

Phrases

unsound mindMental incapacity for decisions

Family

Familiarity: Top 500,000
Profile: Used worldwide · Timeless · Everyday, not technical · Rated G