Joint with soft drink brought round: thanks for the snack (9)
I believe the answer is:
chipolata
'the snack' is the definition.
(type of sausage)
'joint with soft drink brought round thanks' is the wordplay.
'joint with' becomes 'hip' (part of body. I am not sure about the 'with' bit.).
'soft drink' becomes 'cola' (cola is a kind of soft drink).
'brought round' means one lot of letters goes inside another.
'thanks' becomes 'ta' (UK informal version of 'thank you').
'hip' inserted inside 'cola' is 'chipola'.
'chipola'+'ta'='CHIPOLATA'
'for' is the link.
(Other definitions for chipolata that I've seen before include "Type of sausage" , "Party snack" , "banger" , "Small thin sausage" .)