“KYS” is an acronym that stands for “Kill Yourself.” It is an offensive phrase that is used to insult or provoke someone. It is often used in online chatrooms and social media, and it is considered to be a form of cyberbullying. It is important to remember that this phrase should never be used in a joking or lighthearted manner, as it can be extremely hurtful and damaging to the person on the receiving end.