the Abyss: The Greek word abussos means "bottomless." It often refers to the prison of evil spirits or fallen angels under the surface of the world (Revelation 9:1–2, 11; 11:7; 17:8; 20:1, 3; compare 2 Peter 2:4). The metaphor comes from the apparently bottomless depth of the ocean (the ancients had no means for sounding the ocean depths, so to them it was bottomless).