Roald —, author of 1988 children's book Matilda (4)
I believe the answer is:
dahl
(Other definitions for dahl that I've seen before include "British author, notably of children's books, d.1990" , "Split pulses used in Indian cooking" , "Model" , "Roald - - (deviser of Willy-Wonka)" , "Willy Wonka's creator" .)