allies allies /ˈælaɪz/

noun

1. An alliance of nations joining together to fight a common enemy  ( allies )
   an alliance of nations joining together to fight a common enemy
   

 Allies

1. 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  ( Allies )
   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
   
2. 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  ( Allies )
   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
   

 ally ally /ˈælaɪ/

noun

1. () A friendly nation  ( ally )
   a friendly nation
   
2. () An associate who provides cooperation or assistance  ( ally , friend )
   an associate who provides cooperation or assistance
    He's a good ally in fight
   he's a good ally in fight
   
   

verb

1. Become an ally or associate, as by a treaty or marriage  ( ally )
   become an ally or associate, as by a treaty or marriage
    He allied himself with the Communists
   He allied himself with the Communists