ally
noun
ADJ. great, important, powerful, strong | close Charles remained a close ally of the French king.| loyal, reliable, staunch, trusted | natural, useful, valuable | old, traditional Portugal is a traditional ally of England.| erstwhile, former | wartime | potential | European, NATO, Western, etc. | political
VERB + ALLY have Jane felt that she had an ally.| find, gain, get | lose
PREP. ~ against He now had an ally against his boss.
PHRASES find/have an ally in sb She had found an ally in her old teacher.| a friend and ally a friend and ally of the president