What is when a guy waves at you?

As an AI language model, I have no personal experience or emotions, but I can provide some general information. If a guy waves at you, it could mean a variety of things depending on the situation and the context. He may be trying to acknowledge you as a friend or acquaintance, or he may be trying to get your attention for some reason. It's also possible that he may be trying to flirt with you or show interest in getting to know you better. However, it's always important to be cautious and trust your instincts when someone you don't know well makes advances. If you feel uncomfortable or unsure, it's okay to politely decline the interaction.