Drunk’s greedy: called out for lobster perhaps (9)
I believe the answer is:
shellfish
'for lobster perhaps' is the definition.
(lobster is a kind of shellfish)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for shellfish that I've seen before include "A shrimp, maybe" , "Crustaceans" , "Oysters, cockles, mussels etc" , "paella ingredient" , "provider of pearls?" .)