Fool lover with nothing on (7)
I believe the answer is:
buffoon
'fool' is the definition.
(I know that buffoon is a type of fool)
'lover with nothing on' is the wordplay.
'lover' becomes 'buff' (synonyms).
'with' is a charade indicator (letters next to each other).
'nothing' becomes 'o' (looks like zero - 0).
'buff'+'o'+'on'='BUFFOON'
(Other definitions for buffoon that I've seen before include "comic" , "Ridiculous person" , "Foolish person" , "'Clown, fool (7)'" , "Ludicrous figure" .)