Without source’s origin, do hack job on duchy instead of historian (11)
I believe the answer is:
thucydidean
'without source's origin do hack job' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'duchy instead of historian' is the wordplay.
I cannot really see how this works, but
an anagram of 'duchy' is 'hucyd' which is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'on' acts as a link.
Can you help me to learn more?
(Another definition for thucydidean that I've seen is " Relating to an early Greek historian".)