Civilian
From Halopedia, the Halo wiki
A civilian, according to international humanitarian law, is a person who is not a member of his or her country's armed forces. The term is also often used colloquially to refer to people who are not members of a particular profession or occupation, especially by law enforcement agencies, which often use rank structures similar to those of military units. So far extremely few have been seen in any of the three games, except for the factory workers.