Fruity liqueur base (4)
I believe the answer is:
sloe
'fruity liqueur base' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sloe that I've seen before include "Thorny bush with plum-like fruit" , "Fruit of the blackthorn does't sound fast" , "Fruit steeped in gin to make a liqueur" , "Sour blackthorn fruit" , "Wild plum" .)