"Sus" stands for "suspicious," and it is a term that is often used to express doubt or distrust towards someone or something. It can be seen as rude when used to describe a person, as it implies that they are untrustworthy or have something to hide. However, the meaning of the term can vary depending on context and intent. If someone uses the term "sus" in a lighthearted or joking manner, it is typically not meant to be taken seriously. It's important to consider the context and intent behind someone's words before interpreting them as rude.