Giving up sitting in the auditorium (7)

I believe the answer is:

cession

'giving up' is the definition.
(thesaurus)

'sitting in the auditorium' is the wordplay.
'sitting' becomes 'session' (eg a parliamentary session).
'in the auditorium' shows a homophone (sound like) (ie as heard on a stage).
'session' sounds like 'CESSION'.

(Another definition for cession that I've seen is " Act of surrender".)

I've seen this clue in The Times.

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