Obviously no square dance (4)
I believe the answer is:
ball
'square dance' is the definition.
(thesaurus)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for ball that I've seen before include "Old song: 'After the .... was over'" , "form of entertainment" , "Perhaps a bouncer < 's clog" , "Sphere; function" , "Social function for dancing" .)