Outlaw party involving especially long time with Duke (9)

I believe the answer is:

desperado

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'outlaw' is the definition.
(I know that Desperado is a type of outlaw)

'involving especially long time with duke' is the wordplay.
'involving' is an insertion indicator.
'especially' becomes 'esp' (common abbreviation).
'long time' becomes 'era' (a long period of time).
'with' says to put letters next to each other.
'duke' becomes 'ddo' (I can't explain this - if you can you should believe this answer much more).
'esp'+'era'='espera'
'espera' placed into 'ddo' is 'DESPERADO'.

'party' is the link.

Can you help me to learn more?

(Other definitions for desperado that I've seen before include "Gangster" , "Reckless criminal" , "reckless one" , "Reckless guy" , "Reckless person" .)

I've seen this clue in The Guardian.

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