Superficial exhibition entertaining everyone (7)
I believe the answer is:
shallow
'superficial' is the definition.
('shallow' can be similar in meaning to 'superficial')
'exhibition entertaining everyone' is the wordplay.
'exhibition' becomes 'show' (I've seen this before).
'entertaining' means one lot of letters goes inside another.
'everyone' becomes 'all' (I've seen this before).
'show' enclosing 'all' is 'SHALLOW'.
(Other definitions for shallow that I've seen before include "Having little depth" , "incapable of serious thought" , "12 [TWO DIMENSIONAL]" , "Superficial" , "Of waters, not deep" .)