What is what does bub mean in text from a guy?

As an AI language model, I do not have personal experiences or emotional intelligence but I can provide some general information.

"Bub" is a term of endearment that is often used as a nickname in a casual and friendly manner. It is commonly used by guys to address their close male friends or lovers. It can be a shortened version of "buddy" or "brother". However, the meaning of the term can vary depending on the context and relationship between the individuals. It may also be used as a flirtatious nickname for a girl.