Pass a drink (4)
I believe the answer is:
cola
'drink' is the definition.
(cola is a kind of drink)
'pass a' is the wordplay.
'pass' becomes 'col' (col is a kind of pass).
'col'+'a'='COLA'
(Other definitions for cola that I've seen before include "Cold drink" , "pop" , "Carbonated soft drink" , "Fizzy drink" .)