Part of window housing edges of principal display (6)
I believe the answer is:
splash
'display' is the definition.
(thesaurus)
'part of window housing edges of principal' is the wordplay.
'part of window' becomes 'sash' ('sash' is part of 'window').
'housing' is an insertion indicator.
'edges of' suggests removing the centre.
'principal' with its centre taken out is 'pl'.
'sash' enclosing 'pl' is 'SPLASH'.
(Other definitions for splash that I've seen before include "Watery sound" , "Fall in irregular drops" , "Effect of jumping into water" , "Spattering of liquid from sudden disturbance" , "Sound of an object hitting liquid" .)