soundless
1 of 2adjective (1)
sound·less ˈsau̇n(d)-ləs 
: incapable of being sounded : unfathomable
soundless
2 of 2adjective (2)
: making no sound : silent
soundlessly adverb
Synonyms
Adjective (2)
- hushed
- muted
- noiseless
- quiet
- quieted
- silent
- still
- stilly
See all Synonyms & Antonyms 
Word History
Etymology
Adjective (1)
sound entry 6
Adjective (2)
sound entry 1
First Known Use
Adjective (1)
circa 1586, in the meaning defined above
Adjective (2)
1601, in the meaning defined above
soundlessly
adverb
as in silently
Synonyms & Similar Words
Relevance
- silently
- inaudibly
- voicelessly
- noiselessly
- quietly
- feebly
- faintly
- low
- softly
Antonyms & Near Antonyms
- aloud
- audibly
- out
- verbally
- clearly
- vocally
- plainly
- distinctly
- perceptibly
- out loud
- discernibly
- distinguishably