Celebrated Surrealist
I believe the answer is:
ernst
'celebrated surrealist' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ernst that I've seen before include "Max -, twentieth century German Surrealist artist" , "artist's name" , "Young partner" , "German-born painter, Max, co-founder of dadaism, d. 1976" , "Surrealist; stern (anag.)" .)