Lunatic or amusing fool? (9)
I believe the answer is:
ignoramus
'fool?' is the definition.
(I've seen this before)
'lunatic or amusing' is the wordplay.
'lunatic' is an anagram indicator.
'or'+'amusing'='oramusing'
'oramusing' anagrammed gives 'IGNORAMUS'.
(Other definitions for ignoramus that I've seen before include "unwitting person" , "One could be blissful it's said" , "Stupid person" , "Idiot" , "Fool" .)