Intelligent questions heard (4)
I believe the answer is:
wise
'intelligent' is the definition.
(thesaurus)
'questions heard' is the wordplay.
'questions' becomes 'whys'.
'heard' shows a homophone (sound like).
'whys' sounds like 'WISE'.
(Other definitions for wise that I've seen before include "Having good judgement" , "Clever" , "Sagacious" , "Discreet" , "Prudent" .)