Leading figure in Russian opera not exactly roistering? (6)
I believe the answer is:
onegin
'opera not exactly roistering?' is the definition.
I know nothing about this answer so I can't tell whether this works.
'leading figure in russian' is the wordplay.
'leading figure' becomes 'one' (I've seen this in another clue).
'in russian' becomes 'gin' (I can't justify this - if you can you should give a lot more credence to this answer).
'one'+'gin'='ONEGIN'
Can you help me to learn more?
(Other definitions for onegin that I've seen before include "` `Eugene ......' '; Pushkin novel and Tchaikovsky opera" , "Duelling Russian character" , "A leading singer for the opera" .)