ALLY

[noun] [C] - a country that has agreed officially to give help and support to another one, esp. during a war, or a person who helps and supports someone elseThe President said that Britain would remain a vital ally of the United States.North Korea is one of China's staunchest allies.During World War One, Turkey and Germany were allies/Turkey was an ally of Germany.He is generally considered to be the Prime Minister's closest (= greatest) political ally.She described him as a close friend and a dependable ally.The Allies were the countries that fought against Germany, Italy and Japan in World War Two.The Allies were led by the US, the UK, the USSR and France.