Ale (4)
I believe the answer is:
beer
'ale' is the definition.
(ale is a type of beer)
This is all the clue.
(Other definitions for beer that I've seen before include "Drink with a head" , "Hop-flavoured drink" , "Brewery product" , ""Give me a woman who loves __ and I will conquer the world" (Kaiser Wilhelm)" , "The standard English drink" .)