Sphere - party (4)
I believe the answer is:
ball
I believe this clue is a double definition.
'sphere' is the first definition.
(I know that ball is a type of sphere)
'party' is the second definition.
(I know that ball is a type of dance)
(Other definitions for ball that I've seen before include "Round object - dance" , "All-round" , "Bouncer, say" , "Party" , "Throw a dance" .)