a. 无声的, 完全静寂的, 静悄悄的

[ adj ]
marked by absence of sound
<adj.all>
a silent housesoundless footsteps on the grass
the night was still

Soundless \Sound"less\, a.
Not capable of being sounded or fathomed; unfathomable.
--Shak.


Soundless \Sound"less\, a.
Having no sound; noiseless; silent. -- {Sound"less*ly}, adv.
-- {Sound"less*ness}, n.