/ Dictionary / Index A Army of the United States: Meaning and Definition of Find definitions for: Ar'my of the Unit'ed States' Pronunciation: [key] the army or armies referred to in the U.S. Constitution, esp. consisting of the Regular Army, National Guard, and Army Reserve. Cf. United States Army. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Army of the Potomac armyworm Related Content Daily Word Quiz: weary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language