Disfigure chap, breaking leg (6)
I believe the answer is:
Here is my best explanation:
'disfigure' is the definition.
(mangling is a kind of disfiguring)
'chap breaking leg' is the subsidiary indication.
'chap' becomes 'man' (I've seen this before**).
'breaking' indicates an anagram.
'leg' is an anagram of 'gle'.
(Other definitions for mangle that I've seen before include "Ruin", "Old-fashioned laundry appliance", "Crush; old kitchen appliance", "Old-fashioned clothes dryer", "Machine that uses rollers to press", "Press", "Mutilate - clothes wringer", "Mutilate, disfigure", "Old clothes-wringer" and "destroy".)