Mate ringing wife, good for gossipy conversation (7)
I believe the answer is:
chinwag
'gossipy conversation' is the definition.
'mate ringing wife good' is the wordplay.
'mate' becomes 'china' (cockney rhyming slang, mate is china plate).
'ringing' is an insertion indicator.
'wife' becomes 'w'.
'good' becomes 'g' (abbreviation).
'china' enclosing 'w' is 'chinwa'.
'chinwa'+'g'='CHINWAG'
'for' acts as a link.
(Other definitions for chinwag that I've seen before include "Gossip" , "Talk (colloq.)" , "Appoint" , "Conversation (slang)" , "Yak" .)