What (who) is apollyon - definition

The Hebrew term Abaddon (Hebrew: אֲבַדּוֹן ’Ăḇaddōn, meaning "destruction", "doom"), and its Greek equivalent Apollyon (Koinē Greek: Ἀπολλύων, Apollúōn meaning "Destroyer") appear in the Bible as both a place of destruction and an angel of the abyss. In the Hebrew Bible, abaddon is used with reference to a bottomless pit, often appearing alongside the place Sheol (שְׁאוֹל Šəʾōl), meaning the resting place of dead peoples.

In the Book of Revelation of the New Testament, an angel called Abaddon is described as the king of an army of locusts; his name is first transcribed in Koine Greek (Revelation 9:11—"whose name in Hebrew is Abaddon,") as Ἀβαδδών, and then translated Ἀπολλύων, Apollyon. The Vulgate and the Douay–Rheims Bible have additional notes not present in the Greek text, "in Latin Exterminans", exterminans being the Latin word for "destroyer".