An old hand inhabits stage part (5)
I believe the answer is:
apron
'stage part' is the definition.
(part of a stage projecting towards the audience)
'an old hand inhabits' is the wordplay.
'an' becomes 'a'.
'old hand' becomes 'pro' (I've seen this in another clue).
'inhabits' becomes 'n' (I can't justify this - if you can you should believe this answer much more).
'a'+'pro'+'n'='APRON'
Can you help me to learn more?
(Other definitions for apron that I've seen before include "Area around aircraft hangar" , "Aircraft parking area" , "Part of stage in front of the curtain" , "item of clothing in the kitchen" , "Pinnie" .)