Hear silent order (6)
I believe the answer is:
'hear' is the definition.
(I know that hear can be written as listen)
'silent order' is the wordplay.
'order' indicates anagramming the letters.
'silent' is an anagram of 'LISTEN'.
(Other definitions for listen that I've seen before include "Hark!" , "Attend (to a sound)" , "Harken" , "Lend an ear (6)" , "Make an effort to hear" .)