An inflammatory state, it's adjoining Northern Europe (8)
I believe the answer is:
neuritis
'an inflammatory state' is the definition.
'neuritis' can be an answer for 'state' (neuritis is a kind of state). I am not certain of the 'an inflammatory' bit.
'it's adjoining northern europe' is the wordplay.
'it's' becomes 'itis' (I can't justify this - if you can you should give a lot more credence to this answer).
'adjoining' means one lot of letters go next to another.
'northern' becomes 'n' (abbreviation e.g. N. Ireland).
'europe' becomes 'eur' (abbreviation for Europe).
'n'+'eur'='neur'
'itis' after 'neur' is 'NEURITIS'.
Can you help me to learn more?
(Other definitions for neuritis that I've seen before include "Inflammation of nerves" , "Painful condition" , "cause of suffering" , "painful problem" , "Inflammation of a nerve" .)