Sass/sæs/ Definition 1 of 3Pro Tip 1/3Informal Usage Used mainly in casual conversations, not in formal situations. His mom heard the sass and was not amused. Pro Tip 2/3Negative Connotation 'Sass' often implies rudeness and should be used carefully to avoid offending. The waiter's sass made the customers uncomfortable. Pro Tip 3/3Cultural Context Popular in North American culture, and can be seen in movies and TV shows. Popular teen dramas showcase characters with a lot of sass.