WYM
WYM (abbreviation) means Short for "what you mean", used to ask someone to explain what they just said. Example: “wym you're not coming? You promised.”
How to use WYM
Learner’s notesIn plain EnglishIt means "what do you mean?"
Informal messaging only.
Add a question mark if you genuinely want an explanation — without one it reads as an accusation.
Trace the full origin ↓Fill the gap
Can you complete this real example?
_____ you're not coming? You promised.
Etymology
An initialism of what you mean, a clipped form of what do you mean.