Old sailors' tipple (4)
I believe the answer is:
grog
'old sailors' tipple' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for grog that I've seen before include "Rum mixed with water" , "Drink of spirits mixed with water" , "The old sailor's tradition drink" , "Old naval drink" , "Naval rum issue" .)