Clement copying belts - four (9)
I believe the answer is:
forgiving
'clement' is the definition.
(thesaurus)
'copying belts four' is the wordplay.
'copying' becomes 'forging' (forging is a kind of copying).
'belts' means one lot of letters goes inside another (inserted letters are tied or belted up).
'four' becomes 'IV' (Roman numerals).
'forging' placed around 'iv' is 'FORGIVING'.
(Other definitions for forgiving that I've seen before include "Ready to excuse" , "Pardoning" , "Lenient" , "Excusing" , "Giving pardon" .)