Fibre for fashioning sails (5)
I believe the answer is:
sisal
'fibre' is the definition.
(I know that sisal is a type of plant fiber)
'fashioning sails' is the wordplay.
'fashioning' is an anagram indicator.
'sails' is an anagram of 'SISAL'.
'for' is the link.
(Other definitions for sisal that I've seen before include "Fibre from agave plant" , "Fibre-yielding agave" , "Type of fibre" , "Fibrous plant used for rope" , "Rope fibre from leaves of tropical plant" .)