1. Archaic. A special legislative act that imposes a death sentence on a person without a trial.
2. A special legislative act prescribing punishment, without a trial, for a specific person or group. • Bills of attainder are prohibited by the U.S. Constitution (art. I, § 9, cl. 3; art. I, § 10, cl. 1). — Also termed act of attainder. See ATTAINDER; BILL OF PAINS AND PENALTIES . [Cases: Constitutional Law 82.
5. C.J.S. Constitutional Law §§ 429–431.]