Engrave plaque initially unwanted by playwright (5)
I believe the answer is:
inter
'engrave' is the definition.
(put in grave)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for inter that I've seen before include "Prefix meaning between or among" , "Prefix meaning in the middle" , "Bury (or, perhaps, Milan)" , "football team abroad" , "Put underground" .)