Sausage and cool drink passed round volunteers (9)
I believe the answer is:
chipolata
'sausage' is the definition.
(I know that chipolata is a type of sausage)
'cool drink passed round volunteers' is the wordplay.
'cool' becomes 'hip' (hip can mean cool or fashionable).
'drink' becomes 'cola' (cola is a type of drink).
'passed round' indicates putting letters inside.
'volunteers' becomes 'TA' (abbreviation for Territorial Army).
'hip' going into 'cola' is 'chipola'.
'chipola'+'ta'='CHIPOLATA'
'and' is the link.
(Other definitions for chipolata that I've seen before include "Small thin sausage" , "Type of sausage" , "banger" , "Party snack" .)