Basketball venues (6)
I believe the answer is:
arenas
'basketball venues' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for arenas that I've seen before include "Spheres of activity, sporting perhaps" , "Spheres, areas of activity" , "Structures for open-air events" , "Spaces for sports events" , "Central areas of, say, sports stadiums" .)