A claim by a defendant/respondent against a co-defendant/respondent previously named by the plaintiff/claimant.

An action by a defendant in an action against the plaintiff in the same action, upon the same contract, or for the same tort as, if Peter bring an action of trespass against Paul, and Paul bring another action of trespass against Peter, the subject of the dispute being an assault and battery, it is evident that Paul could not set off the assault committed upon him by Peter in the action which Peter had brought against him; therefore the cross action became necessary. Also sometimes known as a cross-action.