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
"The Allied powers, including the major nations that united against the Axis forces during World War II, formally established the foundations for the modern international order by signing the United Nations charter in 1945."
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
"The historical records detail how allies in World War I, including Great Britain, France, and Russia, united to oppose the Central Powers."
an alliance of nations joining together to fight a common enemy
"The allied forces from multiple countries united against their shared adversary."
plural of ally
"The two nations formed a strong alliance after declaring themselves allies against their common enemy."
Third-person singular simple present indicative form of ally
"The diplomat tries to ally herself with neighboring nations to secure a stronger defense pact."
In plain English: To ally with someone means to join forces and work together toward a common goal.
"The two nations decided to ally with each other to ensure their mutual safety against potential threats."
The countries allied against the Axis Powers during World War II. The major signatories included the Soviet Union, Britain, France, United States, Canada, and China.
"The team included two former basketball players, Mike and his allies Sarah and Tom."
plural of Allie
The word allies is simply the standard English plural form of ally. It entered the language as a noun meaning those who join together for mutual help or support.