HMU stands for ‘hit me up’. It’s slang and in this context it means call me or text me. For example, someone may write ‘I’m bored hmu’. It would mean that someone has nothing to do and asks you to invite him/her to do something together. It is extremely informal and I would not recommend using it with someone you don’t know well.

Hmu can be used in texting, while ‘hit me up’ is appropriate for very informal conversations only.

The dictionary says that hit me up means to ask somebody for something, such as ask for money, for example. It’s only up to you to decide whether in your situation it can make some sense…

Hmu means call me or otherwise contact me when I am bored or when I am offline. It was one of the most popular Facebook statuses back in 2010. The official statistics says that in that year about 1,600 statuses a day had hmu in them.