A source of friction -- just business (6)

I believe the answer is:

affair

'business' is the definition.
(thesaurus)

'a source of friction just' is the wordplay.
'source of' suggests taking the first letters.
'just' becomes 'fair' ('fair' is associated in meaning with 'just').
The initial letter of 'friction' is 'f'.
'a'+'f'+'fair'='AFFAIR'

(Other definitions for affair that I've seen before include "Sexual liaison - concern" , "Vaguely specified concern" , "Amorous liaison" , "See 23" , "Secret sexual relationship" .)

I've seen this clue in The Telegraph.

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