Great deal makes sense (5)
I believe the answer is:
sight
I believe this clue is a double definition.
'great deal' is the first definition.
(I know that great deal can be written as sight)
'sense' is the second definition.
(sight or vision is a sense)
'makes' is the link.
(Other definitions for sight that I've seen before include "monstrosity" , "Spectacle; aiming aid" , "Field of vision" , "Range of vision" , "Aiming device on gun" .)