Tea-time chinwag (4)
I believe the answer is:
chat
'chinwag' is the definition.
(I've seen this before)
'tea-time' is the wordplay.
'tea' becomes 'cha' (cha is a type of tea).
'time' becomes 't'.
'cha'+'t'='CHAT'
(Other definitions for chat that I've seen before include "Communication" , "(13) [FRENCH] Cat" , "Friendly talk" , "Natter" , "waffle?" .)