The word "wdym" is an abbreviation for "what do you mean?" It is commonly used in text messaging and online conversations to ask for clarification about something someone has said. When you encounter something that is unclear or confusing, you can respond with "wdym" to prompt the other person to elaborate.
The abbreviation "wdym" is derived from the initial letters of the phrase "what do you mean?" It has emerged with the rise of digital communication, where brevity is preferred for quick exchanges.