Crease new fabric (5)
I believe the answer is:
linen
'fabric' is the definition.
(I know that linen is a type of fabric)
'crease new' is the wordplay.
'crease' becomes 'line' (synonyms).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'line'+'n'='LINEN'
(Other definitions for linen that I've seen before include "Fabric made from flax" , "Type of cloth" , "given blanket coverage" , "E.g. bedclothes" , "sheets, perhaps" .)