Material found in ebony longbow (5)
I believe the answer is:
nylon
'material' is the definition.
(nylon is a kind of material)
'in ebony longbow' is the wordplay.
'in' indicates the answer is hidden within the clue.
'NYLON' is hidden within 'ebony longbow'.
'found' acts as a link.
(Other definitions for nylon that I've seen before include "Fibrous material" , "Type of material" , "Synthetic polymer" , "Artific ial (stocking) material" , "Tights material" .)