Block request for woven material (6)
I believe the answer is:
damask
'woven material' is the definition.
(I've seen this before)
'block request' is the wordplay.
'block' becomes 'dam' (damming is a kind of blocking).
'request' becomes 'ask' (to ask is to request something).
'dam'+'ask'='DAMASK'
'for' acts as a link.
(Other definitions for damask that I've seen before include "reversible material" , "Silk or linen material woven with pattern on either side" , "Material, originally Syrian" , "Patterned cloth" , "Patterned material" .)