Heavy drinker getting very rich (4)
I believe the answer is:
lush
I believe this clue is a double definition.
'heavy drinker' is the first definition.
(I've seen this before)
'very rich' is the second definition.
(I've seen this before)
'getting' is the link.
(Other definitions for lush that I've seen before include "Of growth, profuse and abundant" , "dipsomaniac?" , "Succulent - heavy drinker" , "Green and growing abundantly" , "sponge" .)