Plant fibre used for making rope (5)
I believe the answer is:
sisal
'plant fibre used for making rope' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for sisal that I've seen before include "Type of fibre" , "Fibre from agave plant" , "material for painter, say?" , "Plant fibre used for making rope" , "Plant fibre used to make string" .)