Jargon I allow, having talked turkey first (12)
I believe the answer is:
gobbledegook
'jargon' is the definition.
(I have seen 'Unintelligible jargon' mean 'gobbledegook' so perhaps 'jargon' could also mean 'gobbledegook')
'i allow having talked turkey first' is the wordplay.
I cannot quite see how this works, but
'i' could be 'ego' ('I' in Latin) and 'ego' is located in the answer.
'allow' could be 'le' (I've seen this in other clues) and 'le' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for gobbledegook that I've seen before include "Unintelligible jargon" , "Unreadable jargon" , "incoherent speech" , "Load of tripe" , "pompous jargon" .)