verb.
Third-person singular simple present indicative form of ally.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
in World War I the alliance of Great Britain and France and Russia and all the other nations that became allied with them in opposing the Central Powers
noun.
an alliance of nations joining together to fight a common enemy
noun.
the alliance of nations that fought the Axis in World War II and which (with subsequent additions) signed the charter of the United Nations in 1945
Word Usage
"For the risk that the leaders of a rogue state will use nuclear, chemical, or biological weapons against us or our allies is the greatest security threat we face."