Apollyon - (Easton's Bible Dictionary)
Destroyer, the name given to the king of the hosts represented by the locusts (Rev. 9:11). It is the Greek translation of the Hebrew Abaddon (q.v.).
Apollyon - (Webster's 1828 Dictionary)
APOL'LYON, n. [Gr. destroying.]
The destroyer; a name used Rev 9:11, for the angel of the bottomless pit, answering to the Hebrew Abaddon.
Find in Bible Concordance