Rifle protecting a revolutionary, or an officer (10)

'an officer' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.

'rifle protecting a revolutionary or' is the wordplay.
'rifle' becomes 'carbine' (carbine is a kind of rifle).
'protecting' indicates putting letters inside (inserted letters are held or protected).
'revolutionary' says the letters should be written backwards.
'or' backwards is 'ro'.
'carbine' going around 'a' is 'carabine'.
'carabine'+'ro'='CARABINERO'

Can you help me to learn more?