MILITIA

militia, reserves

(noun) civilians trained as soldiers but not part of the regular army

militia

(noun) the entire body of physically fit civilians eligible by law for military service; “their troops were untrained militia”; “Congress shall have power to provide for calling forth the militia”--United States Constitution

Source: WordNet® 3.1

Etymology

Noun

militia (plural militias or militiae)

An army of trained civilians, which may be an official reserve army, called upon in time of need, the entire able-bodied population of a state which may also be called upon, or a private force not under government control.

The national police force of certain countries (e.g. Belarus).

Source: Wiktionary

Mi*li"tia, n. Etym: [L., military service, soldiery, fr. miles, militis, soldier: cf. F. milice.]

1. In the widest sense, the whole military force of a nation, including both those engaged in military service as a business, and those competent and available for such service; specifically, the body of citizens enrolled for military instruction and discipline, but not subject to be called into actual service except in emergencies. The king's captains and soldiers fight his battles, and yet... the power of the militia is he. Jer. Taylor.

2. Military service; warfare. [Obs.] Baxter.

Source: Webster’s Unabridged Dictionary 1913 Edition