Make small talk (4)
'make small talk' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for chat that I've seen before include "Communication" , "Tom in 22 [ALSACE]" , "Chinwag" , "Have friendly informal conversation" , "Informal conversations" .)
(Other definitions for chitchat that I've seen before include "Idle nattering" , "Idle talk" , "Light informal conversation" , "Informal talk" , "rabbit" .)