Hemp (8)
I believe the answer is:
cannabis
'hemp' is the definition.
(cannabis is a kind of hemp)
This is all the clue.
(Other definitions for cannabis that I've seen before include "Hemp plant for making intoxicant drug" , "Soft drug" , "illegal drug supply" , "Strangely, Incas ban this drug" , "Ban Incas from using this drug" .)