Fibre taken from new sails (5)
I believe the answer is:
sisal
'fibre' is the definition.
(I know that sisal is a type of plant fiber)
'new sails' is the wordplay.
'new' indicates anagramming the letters.
'sails' anagrammed gives 'SISAL'.
'taken from' acts as a link.
(Other definitions for sisal that I've seen before include "Plant producing rope" , "Plant fibre used for making rope" , "Agave yielding fibre" , "Type of fibre" , "Plant fibre used for ropes" .)