What is ARMY? Definition of ARMY in Black's Law Dictionary
The armed forces of a nation intended for military service on land.
An "army" is a body of men whose business is war, while the "militia" is a body of men composed of citizens occupied temporarily in the pursuit of civil life, but organized by discipline and drill, and called into the field for temporary military service when the exigencies of the country require it. And see Brown v. Soldiers' Bonus Board, 44 R.I. 483, 116 A. 280, 281.
—Regular army. The permanent military establishment, which is maintained both in peace and war according to law. 10 U.S.C.A. § 3; State v. Moorhead, 102 Neb. 276, 167 N.W. 70, 71.
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That's the definition of in Black's Law Dictionary - Courtesy of Cekhukum.com.