Crazy, dropping head to the back (3)
I believe the answer is:
aft
'the back' is the definition.
(I've seen this in other clues)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for aft that I've seen before include "Rear part" , "behind boat" , "At the back of a ship" , "Near the rear (of ship)" , "Of ship, fat in the rear" .)