Reserved for the cast (3)
I believe the answer is:
shy
I believe this is a double definition.
'reserved' is the first definition.
(I've seen this before)
'the cast' is the second definition.
(both can mean to throw or fling)
'for' acts as a link.
(Other definitions for shy that I've seen before include "Coy" , "Fling or throw" , "Timid (around people)" , "Timid and self-conscious" , "Nervous with others" .)