impleader

noun | \ im-ˈplē-dər \ | im·plead·er
  1. : the act or procedural device of impleading a third party; specifically : a petition or complaint brought in a lawsuit by a plaintiff or defendant against a third party who may be liable to that plaintiff or defendant — called also third-party practice ; compare counterclaim, cross-claim, interpleader, intervention, joinder : a petition or complaint brought in a lawsuit by a plaintiff or defendant against a third party who may be liable to that plaintiff or defendant — called also third-party practice ; compare counterclaim, cross-claim, interpleader, intervention, joinder