Pairs originally from Bolshoi lead Roman dance (6)
I believe the answer is:
bolero
'dance' is the definition.
(I know that bolero is a type of dance)
I cannot understand how the remainder of the clue works.
(Other definitions for bolero that I've seen before include "Arrange to rob Leo during the dance" , "Lively Spanish dance" , "Rob Leo of his short jacket" , "Spanish dance; Ravel's best-known work" , "Ravel work; jacket" .)