Crossword Genius

Brazilian city as far as we're concerned ungovernable (7)

Ross

I believe the answer is:

riotous

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'ungovernable' is the definition.
Both the answer and definition are adjectives. Perhaps they are linked in a way I don't understand?

'brazilian city as far as we're concerned' is the wordplay.
'brazilian city' becomes 'Rio' (Rio de Janeiro).
'as far as we're concerned' becomes 'to us' (as things appear to us).
'rio'+'tous'='RIOTOUS'

Can you help me to learn more?

(Other definitions for riotous that I've seen before include "Hilariously funny" , "Behaving wildly" , "Anarchic" , "Rowdy" , "Rollicking" .)

I've seen this clue in The Telegraph.
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