What is (a) A post or station without the limits of a camp, or at a distance from the main body of an army, for observation of the enemy. (b) The troops placed at such a station called?

outpost — (a) A post or station without the limits of a camp, or at a distance from the main body of an army, for observation of the enemy. (b) The troops placed at such a station. (Webster's 1913.)

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