Court in celebrity bedroom (4,7)
I believe the answer is:
star chamber
'court' is the definition.
(Star Chamber is an example)
'celebrity bedroom' is the wordplay.
'celebrity' becomes 'star' (I've seen this before).
'bedroom' becomes 'chamber' ('chamber' can be a synonym of 'bedroom').
'star'+'chamber'='STAR CHAMBER'
'in' acts as a link.
(Other definitions for star chamber that I've seen before include "Old-fashioned court" , "Tyrannical court" , "Court abolished in 1641" , "tribunal" , "Old court" .)