Retain alcoholic drink as memento (8)
I believe the answer is:
keepsake
'memento' is the definition.
(I've seen this before)
'retain alcoholic drink' is the wordplay.
'retain' becomes 'keep' (keeping is a kind of retaining).
'alcoholic drink' becomes 'sake' (sake is a kind of drink. I am not sure about the 'alcoholic' bit.).
'keep'+'sake'='KEEPSAKE'
'as' is the link.
Can you help me to learn more?
(Other definitions for keepsake that I've seen before include "Something of sentimental value" , "Thing retained in memory of giver" , "token" , "to remember one by" , "It serves to keep a person in mind" .)