Pine tree leaf (6)
I believe the answer is:
needle
'pine tree leaf' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for needle that I've seen before include "Hostility - annoy - sewing tool" , "Continually annoy" , "Annoy, tantilise" , "Annoy, tantalise" , "Bug" .)