Stroke new material (5)
I believe the answer is:
linen
'material' is the definition.
(linen is a kind of material)
'stroke new' is the wordplay.
'stroke' becomes 'line' (stroke can mean a line or bar).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'line'+'n'='LINEN'
(Other definitions for linen that I've seen before include "E.g. bedclothes" , "Flax textile" , "Fabric made from flax" , "More than one sheet" , "fabricated? This is" .)