among the ancient Romans, a kind of work-house or private prison, usually attached to farms, where the slaves were made to work in fetters. It was usually under ground; and from this dungeon the unhappy inmates were led forth in chains to cultivate the fields. Confinement in the Ergastulum was also used as a punishment for disobedient or intractable slaves, who frequently experienced in these dungeons great severities. At length, after various enactments for ameliorating the condition of slaves, the ergastula were entirely abolished by Hadrian.—(See Spart., Hadrian, 18; Plutarch, Tib. Graecch. 8.)