WBU Meaning: 

WBU” is a moderately common acronym on the internet and in text. It’s easier than many to figure out based on context, but if you encounter it without any context, it’s nearly impossible to figure out.

WBU is an internet slang initialism used to ask the question What about you? It is often written to answer greetings or conversation starters like How are you? Or WYD, what are you doing?