double-cross
verb [ T ]
uk/ˌdʌblˈkrɒs/ usto trick or cheat someone who trusts you, for example, a business partner:
After recent events in Congress, both Democrats and Republicans felt they had been double-crossed by their party leaders.
double-cross
noun [ C ]
He is accused of jeopardising the talks by fuelling fears among unionists of a double-cross.