Lewis Short
(adjective) : poenālis, e, poena
* Of or belonging to punishment, penal (post-Aug.; esp. freq. in the jurists): opera,Plin. 18, 11, 29, § 112: poenalis aquae dirisque genitae,in the infernal regions,id. 4, 8, 15, § 31: ex lege poenali aquā et igne interdici,by the penal law,Gai. Inst. 1, § 128: actio,Dig. 40, 12, 21: causa,ib. 46, 3, 7: conditio,ib. 22, 2, 5: stipulatio,ib. 19, 2, 54 et saep.— Absol.: poenāles, ĭum, m., men subject to punishment, criminals: carcer poenalium,Cod. Just. 10, 19, 2.—Sup.: inter haec horrenda et poenalissima, exceedingly punishable or criminal, Salv. Avar. 2, 10.— Adv.: poenālĭter, by punishment or penalty (post-class.): reus poenaliter interibat,Amm. 16, 8, 2.
Charlton T. Lewis, Charles Short, A Latin Dictionary