Pass a drink (4)
I believe the answer is:
Here is my best explanation:
'drink' is the definition.
(cola is a kind of drink)
'pass a' is the subsidiary indication.
'pass' becomes 'col' (col is a kind of pass).
(Other definitions for cola that I've seen before include "Fizzy drink", "pop", "Drink", "Carbonated soft drink", "Soft drink" and "Cold drink".)