1590, "system of military discipline," from L. militia
"military service, warfare," from miles
"soldier" (see military
). Sense of "citizen army" (as distinct from professional soldiers) is first recorded 1696, perhaps from Fr. milice.
In U.S. history, "the whole body of men declared by law amenable to military service, without enlistment, whether armed and drilled or not" (1777).