Without more context, it's difficult to determine the meaning of "bichi" in this context. It's possible that "bichi" is a slang term or a word in another language. If your friend won't tell you its meaning, it's best to ask them directly or try to understand the context in which they're using it. If "bichi" doesn't seem to have a clear meaning or if it's causing confusion, you could express to your friend that you're unsure of its meaning and ask them to clarify or stop using it if it's causing discomfort or confusion.