Eg Man Ray in county mostly associated with top people (10)
I believe the answer is:
surrealist
'eg man ray' is the definition.
(I know that Man Ray was a surrealist)
'county mostly associated with top people' is the wordplay.
'county' becomes 'surrey' (English county).
'mostly' means to remove the last letter (most but not all of the word).
'associated with' means one lot of letters go next to another.
'top people' becomes 'alist' (A-list).
'surrey' with its last letter taken off is 'surre'.
'surre'+'alist'='SURREALIST'
'in' acts as a link.
(Other definitions for surrealist that I've seen before include "Breton, say" , "Avant-garde artist" , "Dali or Magritte, for example" , "Magritte perhaps" .)