BO

People typically use BO when calling attention to someone's stinky body odor. For example, your friend Mike might text you "Sorry about my BO at lunch today; I came straight from the gym," to apologize for how unpleasant he smelled earlier. (It's too late to apologize now, Mike! We already had to smell you!)

BO is a fairly common acronym (and occurrence), so you may encounter it in text messages, on forums, and even on social media, when people are discussing body odor. Many of these discussions revolve around the "correct" way to tell someone who noticeably stinks about their bad BO.

A StarCraft term that refers to the order in which the player builds structures and units.

If you want someone to leave you alone, send them "BO," which stands for "back off." Of course, you could also send them the other BO (body odor), and they would back off quickly.

Most people use BO online when messaging and in texts when they need a person to give them space, whether literally or figuratively. For example, if your friend makes fun of someone's haircut, they might send them, "BO, at least I don't live with my mom!"