Has no knowledge of argot used in the north (8)
I believe the answer is:
ignorant
'has no' is the definition.
Both the answer and definition are adjectives. Perhaps there's an association between them I don't understand?
'knowledge of argot used in the north' is the wordplay.
I cannot really understand how this works, but
'of' could be 'o' and 'o' is found in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
'north' could be 'n' (abbreviation) and 'n' is found in 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 ignorant that I've seen before include "Poorly-educated" , "Ill-educated" , "Unenlightened" , "Empty-headed" , "Ill-mannered" .)