Exposes back end trade - that's crazy (10)
I believe the answer is:
moonstruck
'that's crazy' is the definition.
(I've seen this before)
'exposes back end trade' is the wordplay.
I cannot quite understand how this works, but
'exposes' could be 'moons' (mooning is a kind of exposing) and 'moons' is found in the answer.
'trade' could be 'truck' (I've seen this before) and 'truck' is found within the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for moonstruck that I've seen before include "Lunatic" , "Crazy" .)