Material John Wayne originally rejected (4)
I believe the answer is:
wool
'material' is the definition.
(wool is a kind of material)
'john wayne originally rejected' is the wordplay.
'john' becomes 'loo' (loo is a kind of john).
'originally' says to take the initial letters.
'rejected' is a reversal indicator.
The initial letter of 'wayne' is 'w'.
'loo'+'w'='loow'
'loow' back-to-front is 'WOOL'.
(Other definitions for wool that I've seen before include "It could become felt" , "Pull this over the eyes to deceive" , "Yarn spun" , "Sheep's yarn" , "Fabric made from animal hair" .)