Ball made square somehow (10)
I believe the answer is:
masquerade
'ball' is the definition.
(masquerade ball is a kind of ball)
'made square somehow' is the wordplay.
'somehow' indicates anagramming the letters.
'made'+'square'='madesquare'
'madesquare' anagrammed gives 'MASQUERADE'.
(Other definitions for masquerade that I've seen before include "Pretence - masked ball" , "where everyone's wearing the veil" , "Dress up" , "The wearing of disguise" , "False show; pretence" .)