King James Version (KJV) - Revelation 9:11 >

And 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.

Textus Receptus (TR) - Revelation 9:11 >

Καὶ ἔχουσιν ἐφ᾿ αὐτῶν βασιλέα τὸν ἄγγελον τῆς ἀβύσσου· ὄνομα αὐτῷ Ἑβραϊστὶ Ἀβαδδών, καὶ ἐν τῇ Ἑλληνικῇ ὄνομα ἔχει Ἀπολλύων.