Dali, say, certainly entertains king and top celebs (10)
I believe the answer is:
surrealist
'dali' is the definition.
(I've seen this before)
'certainly entertains king and top celebs' is the wordplay.
'certainly' becomes 'sure' (synonyms).
'entertains' is an insertion indicator.
'king' becomes 'R' (abbreviation of Latin rex).
'and' says to put letters next to each other.
'top celebs' becomes 'a list' (A-list).
'sure' going around 'r' is 'surre'.
'surre'+'alist'='SURREALIST'
'say' is the link.
(Other definitions for surrealist that I've seen before include "Avant-garde artist" , "Magritte perhaps" , "Dali or Magritte, for example" , "Breton, say" .)