Revelation 9:11
▸ Hear this chapter, lit word by wordAnd they had a king over them, which is the angel of the bottomless pit, whose name in the Hebrew tongue is Abaddon, but in the Greek tongue hath his name Apollyon.
— Revelation 9:11, King James Version
In other translations
World English Bible (WEB)
They have over them as king the angel of the abyss. His name in Hebrew is "Abaddon," but in Greek, he has the name "Apollyon."
American Standard Version (ASV)
They have over them as king the angel of the abyss: his name in Hebrew is Abaddon, and in the Greek tongue he hath the name Apollyon.
Young's Literal Translation (YLT)
and they have over them a king--the messenger of the abyss--a name <FI>is<Fi> to him in Hebrew, Abaddon, and in the Greek he hath a name, Apollyon.