Small drink that's for shooting party's guide in Scotland (6)
I believe the answer is:
gillie
'shooting party's guide in scotland' is the definition.
(Scottish term for a guide on a hunting expedition)
'small drink that's' is the wordplay.
'small drink' becomes 'gill' (amount of liquid equal to a quarter of a pint).
'that's' becomes 'ie'.
'gill'+'ie'='GILLIE'
'for' is the link.
(Other definitions for gillie that I've seen before include "Scottish attendant for fisherman or shooter" , "Hunter's aide" , "Scottish attendant for someone fishing or shooting" , "In Scotland, attendant for person shooting or fishing" , "guide for anglers" .)