cross-claim

noun
  1. : a claim against a party on the same side of an action (as a coplaintiff or codefendant) — compare counterclaim, cross-action, cross-appeal, third-party claim

    Note: Under Rule 13(g) of the Federal Rules of Civil Procedure, a cross-claim must be related to the original action in that it arises from the same transaction or occurrence as the original action or a counterclaim, or involves property that is the subject matter of the original action.