My voice enthrals southern pirate (7)
I believe the answer is:
corsair
'pirate' is the definition.
(I know that corsair is a type of pirate)
'my voice enthrals southern' is the wordplay.
'my' becomes 'cor' (both are expressions of surprise).
'voice' becomes 'air' (I've seen this before).
'enthrals' is an insertion indicator.
'southern' becomes 's' (abbreviation).
'cor'+'air'='corair'
'corair' enclosing 's' is 'CORSAIR'.
(Other definitions for corsair that I've seen before include "Privateer" , "Marauder" , "A swift pirate ship" , "Pirate from N. Africa" , "Main villain" .)