Clownish, madcap (4)
I believe the answer is:
zany
I believe this clue is a double definition.
'clownish' is the first definition.
(I know that clownish can be written as zany)
'madcap' is the second definition.
(I've seen this in another clue)
(Other definitions for zany that I've seen before include "old assistant clown" , "Comically eccentric" , "Left-field - foolish" , "Like a buffoon" , "Amusingly idiosyncratic" .)