double-cross
From Longman Dictionary of Contemporary Englishdouble-crossˌdouble-ˈcross verb [transitive] CHEATto cheat someone, especially after you have agreed to do something dishonest with them —double cross noun [countable] —double-crosser noun [countable]→ See Verb tableExamples from the Corpusdouble-cross• Harry and Danny double-crossed the gang and escaped with all the money.From Longman Business Dictionarydouble-crossˌdouble-ˈcross verb [transitive] to cheat someone who you are involved in an illegal or dishonest activity withHe was living in fear of drug traffickers he had double-crossed.→ See Verb table