The Collaborative International Dictionary of English v.0.48:
Command \Com*mand"\, n.
1. An authoritative order requiring obedience; a mandate; an
Awaiting what command their mighty chief
Had to impose. --Milton.
2. The possession or exercise of authority.
Command and force may often create, but can never
cure, an aversion. --Locke.
3. Authority; power or right of control; leadership; as, the
forces under his command.
4. Power to dominate, command, or overlook by means of
position; scope of vision; survey.
The steepy stand
Which overlooks the vale with wide command.
5. Control; power over something; sway; influence; as, to
have command over one's temper or voice; the fort has
command of the bridge.
He assumed an absolute command over his readers.
6. A body of troops, or any naval or military force or post,
or the whole territory under the authority or control of a
Word of command (Mil.), a word or phrase of definite and
established meaning, used in directing the movements of
soldiers; as, aim; fire; shoulder arms, etc.
Syn: Control; sway; power; authority; rule; dominion;
sovereignty; mandate; order; injunction; charge; behest.