Make an impact on that will leave a lasting impression (4)
I believe the answer is:
dent
This could be a double definition.
'make an impact on that will' is the first definition.
'dent' can be an answer for 'make an impact' (I've seen this in another clue). I am not certain of the remainder of the definition.
'a lasting impression' is the second definition.
(I've seen this in another clue)
'leave' acts as a link.
Can you help me to learn more?
(Other definitions for dent that I've seen before include "Impress" , "'Dinge, depression (4)'" , "Tend (anag.)" , "A cavity" , "Hollow caused by a blow" .)