Ancient writing material (7)
I believe the answer is:
papyrus
'ancient writing material' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for papyrus that I've seen before include "Kind of paper used in old Egyptian manuscripts" , "Egyptian material for writing on" , "Paper made from reeds" , "Egyptian writing matter" , "old document" .)