Drink for cast (5)
I believe the answer is:
sling
I believe this clue is a double definition.
'drink' is the first definition.
(sling is a kind of drink)
'for cast' is the second definition.
(cast can mean to throw or sling)
(Other definitions for sling that I've seen before include "Arm support; hurl" , "Sweetened drink with spirit base" , "shy" , "Simple weapon; throw" , "Primitive weapon" .)