legion, host - archaic terms for army

army unit - a military unit that is part of an army

armed service, military service, service - a force that is a branch of the armed forces

armed forces, armed services, military, military machine, war machine - the military forces of a nation; "their military is the largest in the region"; "the military machine is the same one we faced in 1991 but now it is weaker"

corps - an army unit usually consisting of two or more divisions

standing army - a permanent army of paid soldiers

Union Army - the northern army during the American Civil War

Army of the Confederacy, Confederate Army - the southern army during the American Civil War

Continental Army - the American army during the American Revolution

U. S. Army, United States Army, US Army, USA - the army of the United States of America; organizes and trains soldiers for land warfare