Firm with citizen adopting facade - they're so argumentative (15)
I believe the answer is:
confrontational
'so argumentative' is the definition.
I can't tell whether this definition defines the answer.
'firm with citizen adopting facade' is the wordplay.
'firm' becomes 'co' (a firm is a company).
'with' means one lot of letters go next to another.
'citizen' becomes 'national' (national can mean a citizen of a country).
'adopting' is an insertion indicator (inserted letters are taken on or adopted).
'facade' becomes 'front' (I've seen this before).
'national' placed around 'front' is 'nfrontational'.
'co'+'nfrontational'='CONFRONTATIONAL'
'they're' is the link.
Can you help me to learn more?
(Other definitions for confrontational that I've seen before include "Dealing hostilely with others" , "wanting to encourage hostility" , "Aggressively hostile" , "Openly hostile" .)