Pirate's reportedly crude manner (7)

I believe the answer is:

corsair

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'pirate's' is the definition.
(corsair is a kind of pirate)

'reportedly crude manner' is the wordplay.
'reportedly crude' becomes 'cors' (I can't explain this - if you can you should give a lot more credence to this answer).
'manner' becomes 'air' (air is a kind of manner).
'cors'+'air'='CORSAIR'

Can you help me to learn more?

(Other definitions for corsair that I've seen before include "Buccaneer" , "20 across" , "Marauder" , "Barbary pirate - pirate ship" , "A swift pirate ship" .)

I've seen this clue in The Telegraph.

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