chit
A slip of paper that one signs to indicate money owed, in lieu of a formal payment. The owner was kind enough to give me a chit after she heard that I'd forgotten my wallet at home.
chitchat
1. verb To talk in an idle or casual manner. We're just chitchatting, come on in.
2. noun An instance of idle or casual chatter. We're just having a chitchat, come on in.