The Collaborative International Dictionary of English v.0.48:

Chat \Chat\ (ch[a^]t), v. i. [imp. & p. p. Chatted; p. pr. &
   vb. n. Chatting.] [From Chatter. [root]22.]
   To talk in a light and familiar manner; to converse without
   form or ceremony; to gossip. --Shak.
   [1913 Webster]

         To chat a while on their adventures.     --Dryden.

   Syn: To talk; chatter; gossip; converse.
        [1913 Webster]