Apollyon (Gr. the destroyer), used in Rev. ix. 11 as a translation of the Hebrew abaddon. In the Old Testament abad-don signifies the subterranean region, or place of the dead, equivalent to the Greek Hades. The rabbins, however, divide this region into two portions, the upper being the grave, the lower abaddon, founding this distinction especially upon Ps. lxxxviii. 11, "Shall thy loving kindness be declared in the grave, or thy faithfulness in destruction [abaddon] ? " In Revelation Apollyon is personified as the angel who has dominion over the bottomless pit, the chief of the destroying agents, represented under the figure of locusts, who emerge from the abyss at the sounding of the fifth trumpet. Some apocalyptic expositors have held that the locusts represent the Saracens, and that Apollyon means especially Mohammed; but it is more likely that the figure is a general representation of the convulsions attending the breaking down of paganism and the establishment of Christianity. In the "Pilgrim's Progress " Apollyon is the name of the evil spirit encountered by Christian in the valley of the shadow of death; hence the word has come to be almost a synonyme for the chief of the fallen angels.