I crave - a form of greed (7)
I believe the answer is:
avarice
'greed' is the definition.
(synonyms)
'i crave a form' is the wordplay.
'form' is an anagram indicator (another form of the letters).
'i'+'crave'+'a'='icravea'
'icravea' anagrammed gives 'AVARICE'.
'of' is the link.
(Other definitions for avarice that I've seen before include "Extreme greed for wealth" , "A deadly sin" , "Wanting to be rich" , "Cupidity" , "excessive desire for wealth" .)