silent

adjective

1. 1

   unable to speak because of hereditary deafness

2. 2

   having a frequency below or above the range of human audibility

   a silent dog whistle

3. 3

   not made to sound

   the silent `h' at the beginning of `honor'

   in French certain letters are often unsounded

4. 4

   failing to speak or communicate etc when expected to

   the witness remained silent

5. 5

   implied by or inferred from actions or statements

   gave silent consent

   a tacit agreement

6. 6

   marked by absence of sound

   a silent house

   soundless footsteps on the grass