This rare verb means to throw into Tartarus, the deepest pit of the Greek underworld, deeper than Hades itself. Peter uses it once (2 Pet 2:4) to describe God's judgment on sinning angels, casting them into gloomy chains in the abyss. The term draws on Greek mythology but applies it to biblical angelology. No language translates it simply as 'cast down'—most transliterate or explain 'cast into Tartarus,' recognizing the specific theological geography involved. This is consignment to the lowest prison of the cosmos.