To converse in an easy, familiar manner; talk lightly and casually. Computers To participate in a synchronous exchange of remarks with one or more people over a computer network. An informal, light conversation. Computers A synchronous exchange of remarks over a computer network. Any of various birds in the families Muscicapidae or Parulidae that have a chattering call, especially the yellow-breasted chat. To engage (someone) in light, casual talk:"He would be .. chatting up folks from Kansas"(Vanity Fair). To talk informally with (someone), especially in a flirtatious manner.