The word "sassy" is used to describe someone who is bold, outgoing, and confident, often in a way that is cheeky or irreverent. A sassy person might have a sharp wit and speak in a way that challenges authority or societal norms, frequently using humor or sarcasm.
The word "sassy" is believed to be derived from the term "saucy," which comes from Middle English "sawcy," meaning "impudent" or "insolent." It can also be connected to the word "sauce," implying a certain spiciness or piquancy in a manner or attitude. The informal use of "sassy" in American English became popular in the 19th century.