"London Fields” author Martin (4)
I believe the answer is:
amis
'london fields author martin' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for amis that I've seen before include "English writer" , "Kingsley -, English author (Lucky Jim)" , "Kingsley, Martin or John" , "Martin --, Eng. author" , "Author of Lucky Jim, d.1995" .)