Roald —, author of 1964 children's book Charlie and the Chocolate Factory (4)
I believe the answer is:
dahl
(Other definitions for dahl that I've seen before include "British writer of many children's books, d. 1990" , "Roald - - (deviser of Willy-Wonka)" , "Roald -, Br. author" , "Indian dish of legumes and spices" , "British writer notably of children's books" .)