Sing out for drinks! (4)
I believe the answer is:
gins
'for drinks' is the definition.
(gin is a kind of drink)
'sing out' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'sing' is an anagram of 'GINS'.
(Other definitions for gins that I've seen before include "Drinks; traps" , "Sings badly for drinks" , "Alcoholic drinks" .)