Establishment play for time beset by independent people (12)
I believe the answer is:
installation
'establishment' is the definition.
(thesaurus)
'play for time beset by independent people' is the wordplay.
'play for time' becomes 'stall' (I've seen this before).
'beset by' is an insertion indicator ('beset' could historically mean 'cover').
'independent' becomes 'i'.
'people' becomes 'nation'.
'i'+'nation'='ination'
'stall' put inside 'ination' is 'INSTALLATION'.
(Other definitions for installation that I've seen before include "Apparatus positioned" , "Positioning" , "Large gallery artwork" , "Art exhibit in gallery" , "A setting up; equipment so set" .)