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