Reportedly wished not to have been ignorant (4)
I believe the answer is:
rude
'ignorant' is the definition.
(thesaurus)
'reportedly wished not to have been' is the wordplay.
'reportedly' shows a homophone (sound like).
'wished not to have been' becomes 'rued' (to rue is to regret).
'rued' is a homophone of 'RUDE'.
(Other definitions for rude that I've seen before include "Uncivil" , "Ill-mannered; hearty" , "Coarse, unpolished" , "Impolite; unpolished" , "Coarse or discourteous" .)