Rich drunkard (4)
I believe the answer is:
lush
I believe this clue is a double definition.
'rich' is the first definition.
(similar in meaning)
'drunkard' is the second definition.
(I know that lush is a type of drunkard)
(Other definitions for lush that I've seen before include "Growing thickly; drunkard" , "Growing thickly; succulent" , "one mortal too often" , "Habitual drinker (slang)" , "Of grass, growing thickly and strongly" .)