Reportedly watched part of play (5)
I believe the answer is:
scene
'part of play' is the definition.
(scene in a play)
'reportedly watched' is the wordplay.
'reportedly' indicates a 'sounds like' (homophone) clue.
'watched' becomes 'seen' (I've seen this in another clue).
'seen' sounds like 'SCENE'.
(Other definitions for scene that I've seen before include "site" , "Drama; setting" , "Subdivision of a drama" , "Vista or stage setting" , "Landscape; part of act" .)