Endlessly recommend imbibing a liqueur (8)
I believe the answer is:
advocaat
'liqueur' is the definition.
(I've seen this before)
'endlessly recommend imbibing a' is the wordplay.
'endlessly' means to remove the last letter.
'recommend' becomes 'advocate' (synonyms).
'imbibing' is an insertion indicator (drinking in).
'advocate' with its last letter removed is 'advocat'.
'advocat' going around 'a' is 'ADVOCAAT'.
(Other definitions for advocaat that I've seen before include "Liqueur (for lawyers?)" , "Liqueur made from eggs, sugar and brandy" , "Egg and rum drink" , "Liquer of eggs, sugar and brandy" , "Booze" .)