Words have meaning. The Words chosen by the Holy Spirit in Holy Writ have meaning. We need to be willing to diligently discover the meaning of those Words.
ABADDON - in the Old Testament, a place name of the realm of the dead. Three times in the Old Testament Abaddon is paralledled with Sheol (Job 26:6; Prov. 15:11; 27:20) In Job 28:22 it is equal to death, and in Psalms 88:11 is refers to the grave.
Abaddon belongs to the realm of the mysterious. Only God fully understands it. (Job 26:6; Prov. 15:11) It is the place or world of the dead in its utterly dismal, destructive, and dreadful aspects. In Abaddon there are no declarations of God's lovingkindness, (Psalms 88:11)
In the New Testament the word occurs once (Rev 9:11), the personalization becoming sharp. Abaddon is here not th world of the dead, but the angel who reigns over it. The Greek equivalent of his name is given as Apollyon. 1.
1. W. J. Bdeecher, ISBE, Vol. 1,( Eerdmans: Grand Rapid Michigan), p.2