Intoxicating nonsense! (9)
I believe the answer is:
moonshine
'nonsense' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for moonshine that I've seen before include "Foolish ideas, hooch" , "hard stuff" , "Illicit spirit - foolish talk" , "Light in the still of the night" , "Illicit spirits" .)