Sharpness put wife off piece of cheddar (4)
I believe the answer is:
edge
'sharpness' is the definition.
(I know that sharpness can be written as edge)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for edge that I've seen before include "Guitarist with U2" , "Advantage (informal)" , "Create borders" , "Force" , "Hem" .)