Farewell drink I accepted served up (5)
I believe the answer is:
adios
'farewell' is the definition.
(adios is a kind of farewell)
'drink i accepted served up' is the wordplay.
'drink' becomes 'soda' (soda is a kind of drink**).
'accepted' means one lot of letters goes inside another.
'served up' shows that the letters should be reversed in order.
'soda' placed around 'i' is 'soida'.
'soida' written backwards gives 'ADIOS'.
(Other definitions for adios that I've seen before include "Goodbye (Spanish)" , "Bye-bye (amigo)" , "So long, amigo" , "Adieu, arrivederci" , "See you in Ibiza" .)