Fibre used in ropes is all-purpose (5)
I believe the answer is:
sisal
'fibre' is the definition.
(I know that sisal is a type of plant fiber)
'in ropes is all-purpose' is the wordplay.
'in' indicates a hidden word.
'SISAL' is hidden within 'ropes is all purpose'.
'used' acts as a link.
(Other definitions for sisal that I've seen before include "Ropemaker" , "Fibre used in rope-making" , "constituent of rope" , "Fibre-yielding agave" , "Sails (anag) - fibre" .)