A public square in Roman cities where markets and assemblies for judicial or political purposes were held; hence a court, a tribunal; a place of jurisdiction. The law of the forum is the law of the place where a suit is to be tried. In canon law, internal forum, the realm of conscience, is contrasted with the external or outward forum; thus, a marriage might be null and void in the internal forum, but binding outwardly, i.e.,in the external forum, for want of judicial proof to the contrary.