Noun:
1: us, america, u.s.a., united states of america, the states, united states, usa, u.s. North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776
2: usa, u. s. army, united states army, army, us army the army of the United States of America; the agency that organizes and trains soldiers for land warfare