Champion endlessly consuming a liqueur (8)
I believe the answer is:
advocaat
'liqueur' is the definition.
(I've seen this before)
'champion endlessly consuming a' is the wordplay.
'champion' becomes 'advocate' (I've seen this before).
'endlessly' means to remove the last letter.
'consuming' means one lot of letters goes inside another.
'advocate' with its final letter taken away is 'advocat'.
'advocat' going around 'a' is 'ADVOCAAT'.
(Other definitions for advocaat that I've seen before include "medicinal drink" , "Booze" , "Liqueur made with raw eggs" , "Egg and rum drink" , "Liqueur made from eggs, sugar and brandy" .)