Silent lionesses wandering about (9)
I believe the answer is:
noiseless
'silent' is the definition.
(I've seen this before)
'lionesses wandering about' is the wordplay.
'wandering about' indicates an anagram (I've seen this in other clues).
'lionesses' is an anagram of 'NOISELESS'.
(Other definitions for noiseless that I've seen before include "Mum" , "unsound?" , "Lionesses (anag) - making no sound" , "Silent, quiet" , "with a silencer?" .)