Drink from boozing.org.uk sent back (4)
I believe the answer is:
grog
'drink' is the definition.
(grog is a kind of drink)
'from boozing org uk sent back' is the wordplay.
'from' says the answer is hidden in the clue.
'sent back' shows that the letters should be reversed in order.
'gorg' is hidden in the letters of 'boozing org uk'.
'gorg' reversed gives 'GROG'.
(Other definitions for grog that I've seen before include "Naval rum issue" , "Drink of spirits mixed with water" , "Sailors' drink of rum and water" , "Drink of spirits and water liked by sailors" , "Old naval drink" .)