Max —, German artist whose works include 1940's Attirement of the Bride (5)
I believe the answer is:
ernst
(Other definitions for ernst that I've seen before include "artist's name" , "Max __; Dadaist" , "German-born painter, Max, co-founder of dadaism, d. 1976" , "He painted" , "Surrealist; stern (anag.)" .)