Prickly (6)
I believe the answer is:
thorny
'prickly' is the definition.
(I know that prickly can be written as thorny)
This is the entire clue.
(Other definitions for thorny that I've seen before include "Problematic (question)" , "Tricky" , "Causing difficulty - like a bed of roses?" , "Unpleasant" , "Trying" .)