For dancers, mostly awkward maintaining circle (7)
I believe the answer is:
'for dancers' is the definition.
(Bolshoi Ballet in Russia)
'mostly awkward maintaining circle' is the wordplay.
'mostly' means to remove the last letter.
'awkward' becomes 'bolshy' (I've seen this before).
'maintaining circle' becomes 'oi' (I am not sure about this - if you are sure you should believe this answer much more).
'bolshy' with its last letter removed is 'bolsh'.
(Other definitions for bolshoi that I've seen before include "Moscow's ballet" , "Russian ballet company" , "Great Moscow ballet company" , "Moscow theatre (ballet, etc)" , "Famous Moscow ballet company" .)