Chatty comes from chat + -y. Chat is a shortening of chatter, of imitative origin mimicking rapid talk. The historical trail runs through chateren in Middle English. Morphologically, chatty is transparent: it draws on chat + -y. Used as an adjective, chatty now means "inclined to talk freely and informally", so the present definition can be read against the older forms and meanings. The same lexical family is also visible in derived forms such as chattily and chattiness and related forms such as chat and chatter. The modern word remains analyzable through its parts, which makes the semantic connection unusually direct.