Understanding the tight-fisted (8)
I believe the answer is:
grasping
This clue is a double definition.
'understanding' is the first definition.
(to grasp something is to understand it)
'tight-fisted' is the second definition.
(thesaurus)
'the' acts as a link.
(Other definitions for grasping that I've seen before include "Miserly; seizing" , "Greedy, avaricious" , "Gangs rip, being greedy" , "Holding" , "avaricious attitude" .)