Knocked loudly, entranced (4)
I believe the answer is:
rapt
'entranced' is the definition.
(thesaurus)
'knocked loudly' is the wordplay.
'knocked' becomes 'rapped' ('rap' can be a synonym of 'knock').
'loudly' shows a homophone (sound like).
'rapped' is a homophone of 'RAPT'.
(Other definitions for rapt that I've seen before include "Engrossed, spellbound" , "Gripped" , "Ecstatic in part" , "Delighted" , "Taken up entirely" .)