double–cross

to be unfaithful or disloyal to she promised to share the profits but then double-crossed us Synonyms backstab, cross, double-cross, sell (out), two-timeRelated Words give away; inform (on), peach, rat (on), shop [British], snitch (on), split (on) [British], tell (on), turn inNear Antonyms defend, guard, protect, safeguard, save, shieldAntonyms stand by