Crazy to consume energy drink made from honey (4)
I believe the answer is:
mead
'drink made from honey' is the definition.
(I've seen this before)
'crazy to consume energy' is the wordplay.
'crazy' becomes 'mad' ('mad' can be a synonym of 'crazy').
'to consume' means one lot of letters goes inside another.
'energy' becomes 'e' (physics symbol as in E=mc2).
'mad' going around 'e' is 'MEAD'.
(Other definitions for mead that I've seen before include "Cooked joint" , "something to drink" , "Honey wine" , "Honey drink; lea" , "Drink made of fermented honey and water" .)