noun: (law) A lawsuit that is dismissed as having been brought without cause, prior to an adjudication on the merits.
noun: (law) A neglect or failure by the plaintiff to follow up his suit; a renunciation or withdrawal of the cause by the plaintiff.
verb: (law, transitive) To dismiss (a suit or plaintiff) on the grounds of his or her lawsuit having been brought without cause, prior to an adjudication on the merits.