Talk about bowler, say (4)
I believe the answer is:
chat
'talk' is the definition.
(I know that chat is a more specific form of the action converse)
'about bowler say' is the wordplay.
'about' becomes 'c' (abbreviation for circa).
'bowler say' becomes 'hat' (bowler is a type of hat).
'c'+'hat'='CHAT'
(Other definitions for chat that I've seen before include "Talk informally; bird" , "Talk casually" , "A bird; converse" , "Exchange text or voice messages through a computer" , "Chinwag" .)