Moves silently and carefully (6)
I believe the answer is:
creeps
'moves silently and carefully' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for creeps that I've seen before include "Moves slowly and stealthily" , "willies" , "''Tomorrow, and tomorrow, and tomorrow, ... in this petty pace from day to day'' (Macbeth)" , "'''Tomorrow, and tomorrow, and tomorrow, ... in this petty pace from day to day'' (Shakespeare) (6)'" , "Toadies" .)