Conservative tax? (3)
I believe the answer is:
This clue could be a double definition.
'conservative' is the first definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
'tax?' is the second definition.
(British sales tax)
Can you help me to learn more?
(Other definitions for vat that I've seen before include "Large tank for liquids, or kind of tax" , "Container for liquids" , "Large barrel" , "possible source of liquid" , "Large tank or vessel" .)