Chat informally (6)

'chat informally' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for natter that I've seen before include "Chat casually" , "Casual talk" , "Chit-chat" , "Chat busily" , "Chat away informally" .)
(Other definitions for chinwag that I've seen before include "Talk (sl.)" , "Chat (slang)" , "Move mandible about in informal chat" , "Yak" , "Chat (colloq.)" .)