Clown -- crazy person, a fair attraction? (7)
I believe the answer is:
coconut
'a fair attraction?' is the definition.
(coconut shy is a fairground game)
'clown crazy person' is the wordplay.
'clown' becomes 'coco' (Nicolai Poliakoff aka Coco the Clown).
'crazy person' becomes 'nut' (nut can informally mean an insane person).
'coco'+'nut'='COCONUT'
(Other definitions for coconut that I've seen before include "Flesh" , "Hard-shelled fruit of palm tree with white lining" , "Oval nut with fibrous husk" , "one of a lovely bunch?" , "Hairy, milk-containing fruit of the palm" .)