Talk about Panama, for example (4)
I believe the answer is:
chat
'talk' is the definition.
(chat can mean to talk)
'about panama for example' is the wordplay.
'about' becomes 'c' (circa).
'panama for example' becomes 'hat' (Panama is a type of hat).
'c'+'hat'='CHAT'
(Other definitions for chat that I've seen before include "Talk casually" , "Inconsequential conversation" , "Talk informally; bird" , "Exchange text or voice messages through a computer" , "Friendly talk" .)