Spinach is to fall in value (3)
I believe the answer is:
sag
I believe this is a double definition.
'spinach' is the first definition.
(I have seen 'Indian spinach ' mean 'sag' so perhaps 'spinach' could also mean 'sag')
'fall in value' is the second definition.
(I've seen this in another clue)
'is to' is the link.
(Other definitions for sag that I've seen before include "Hang down loosely" , "Drop" , "Subsidence" , "fall" , "Give way under pressure" .)