Sink port wine, finally getting drunk at party (7)
I believe the answer is:
torpedo
'sink' is the definition.
(I've seen this in another clue)
'port wine finally getting drunk at party' is the wordplay.
'finally' says to take the final letters.
'getting drunk' indicates an anagram.
'at' is a charade indicator (letters next to each other).
'party' becomes 'do' (do can informally mean a party).
The final letter of 'wine' is 'e'.
'port'+'e'='porte'
'porte' is an anagram of 'torpe'.
'torpe'+'do'='TORPEDO'
(Other definitions for torpedo that I've seen before include "Submarine weaponry" , "Explosive underwater projectile" , "Anti-ship weapon" , "Poor Ted (anag)" , "Self-propelled submarine weapon" .)