Leaves PIN to get cash, foolishly (7)
I believe the answer is:
spinach
'leaves' is the definition.
(leafy vegetable)
'pin to get cash foolishly' is the wordplay.
'to get' is an insertion indicator.
'foolishly' is an anagram indicator.
'cash' anagrammed gives 'sach'.
'pin' placed inside 'sach' is 'SPINACH'.
(Other definitions for spinach that I've seen before include "food" , "Some greens" , "Popeye the Sailor's vegetable of choice" , "Vegetable leaves" , "Blackboard stand" .)