Beam, having no new material (5)
I believe the answer is:
rayon
'material' is the definition.
(rayon is a type of fabric)
'beam having no new' is the wordplay.
'beam' becomes 'ray' (synonyms).
'having' says to put letters next to each other.
'no' becomes 'O' (resembles 0 - 'no' can mean 'zero').
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'ray'+'o'+'n'='RAYON'
(Other definitions for rayon that I've seen before include "Cellulose textile fibre" , "Cellulose fabric" , "Or any (anag) -- fibre" , "Man-made fibre" , "Artificial fibre" .)