WYM is an acronym that stands for "what you mean" or "what do you mean". It is used mostly in texting, social media, and online forums to ask for clarification when someone makes a statement that is unclear or open to interpretation. WYM can also begin a rhetorical question, and the question mark is optional because its understood that WYM is asking a question. Sometimes, WYM can mean "watch your mouth," but to know which definition the user intended, you need to look at the context. WYM is a slang term that is informal and should only be used in very informal situations.