Sports arena (7)
I believe the answer is:
stadium
'sports arena' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for stadium that I've seen before include "eg Yankee, Wembley" , "Admit us (anag) - sports ground" , "Large structure for open-air sports" , "Venue for sporting events, concerts etc" , "Sports arena" .)