Fibre used for ropes is aligned (5)
I believe the answer is:
sisal
'fibre' is the definition.
(I know that sisal is a type of plant fiber)
'used for ropes is aligned' is the wordplay.
'used for' indicates a hidden word.
'SISAL' is hidden within 'ropes is aligned'.
(Other definitions for sisal that I've seen before include "Plant fibre used to make string" , "Natural fibre" , "Agave yielding fibre" , "material for painter, say?" , "Plant producing rope" .)