Second-hand (4)
'second-hand' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for used that I've seen before include "Accustomed, having been put into service" , "Worn" , "No longer new" , "Dog-eared" , "with some traffic" .)
(Another definition for pre-owned that I've seen is " Used".)