Bloody Mary ingredient (5)
I believe the answer is:
'bloody mary ingredient' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for vodka that I've seen before include "Russian tipple" , "Colourless alcoholic spirit associated with Russia" , "Russian alcoholic drink" , "Colourless alcohol" , "Spirit traditionally made from fermented grains or potatoes" .)