MIA stands for "missing in action". It is a military term that refers to members of the military who are reported missing during war or a ceasefire. They may have been killed, wounded, captured, or deserted, but their status is unknown. The term is also used figuratively for unexpected absences to say you havent seen someone in a while or cant find them. It is important to note that MIA can also be an acronym for other things, such as "bulimia".