A drink to help make you alert (3)
I believe the answer is:
ale
This might be a double definition.
'a drink' is the first definition.
(ale is a kind of drink)
'make you alert' is the second definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'to help' acts as a link.
Can you help me to learn more?
(Other definitions for ale that I've seen before include "Type of beer" , "English beer in sales" , "Beerlike beverage" , "Stout" , "brew" .)