verb. To betray someone by leading them into trap after having gained their trust and led them to believe that they were actually being aided.

noun. An instance of betrayal of one who has been led to believe that the betrayer was assisting thim.

"Liz: It would seem so, though it was also somewhat implied that Ben planned to doublecross MIB all along -- what with the walkie talkie link to Miles and all."

doublers  

doublecrossing