Collins base (3)
I believe the answer is:
gin
'collins base' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for gin that I've seen before include "Alcoholic drink once known as mother's ruin" , "Machine for separating cotton from its seeds" , "Alcoholic drink made from juniper berries - it's a trap" , "Alcohol made with juniper berries" , "Spirit; cotton machine" .)