The word "bunda" is not a standard English term, but it is sometimes found in different contexts. In certain languages like Portuguese, "bunda" can refer to a person's bottom or backside. In that context, it is often used in informal conversations. Given that it may not be an English word, I will proceed with an assumption that you might be looking for common usages and expressions around it.
The term "bunda" comes from Portuguese, where it colloquially means "butt" or "bottom." It reflects a informal way of referring to the posterior in various cultures where Portuguese is spoken.