Thievish (5-8)
I believe the answer is:
light-fingered
'thievish' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for light-fingered that I've seen before include "Given to thieving" , "Having a propensity for stealing" , "Like a pickpocket" , "Likely to steal" , "Adept at thieving" .)