Child of resonance (3)
I believe the answer is:
son
'child' is the definition.
(male child)
'of resonance' is the wordplay.
'of' indicates a hidden word.
'SON' can be found hidden inside 'resonance'.
(Other definitions for son that I've seen before include "Young boy" , "The kind of child" , "Male scion" , "A relative" , "Express paper" .)