Monopoly token replaced by a cat in 2013 (4)
I believe the answer is:
iron
'monopoly token replaced by a cat in 2013' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for iron that I've seen before include "Smooth - driver?" , "See 14" , "Main element in steel" , "Heavy metal that rusts easily" , "Smooth (clothes)" .)