Greed, for starters, and resulting in a wicked habit (7)
I believe the answer is:
avarice
'greed' is the definition.
(avarice is a kind of greed)
'starters and resulting in a wicked habit' is the wordplay.
'starters' says to take the initial letters.
'in' means one lot of letters goes inside another.
'wicked habit' becomes 'vice' (I've seen this before).
The first letters of 'and resulting' is 'ar'.
'a'+'vice'='avice'
'ar' put inside 'avice' is 'AVARICE'.
'for' is the link.
(Other definitions for avarice that I've seen before include "Excessive greed for wealth" , "Insatiable lust" , "Stinginess" , "Eager desire" , "Greed - caviare (anag)" .)