I do it badly being a fool (5)
I believe the answer is:
idiot
'being a fool' is the definition.
(I've seen this before)
'i do it badly' is the wordplay.
'badly' indicates anagramming the letters (letters in the wrong order).
'do'+'it'='doit'
'doit' is an anagram of 'diot'.
'i'+'diot'='IDIOT'
(Other definitions for idiot that I've seen before include "Dipstick" , "Dope" , "Goose" , "Imbecile" , "nutter" .)