1: διάβολος
(Strong's #1228 — Adjective — diabolos — dee-ab'-ol-os )

"an accuser" (cp. ACCUSE, B, No. 1), is used 34 times as a title of Satan, the Devil (the English word is derived from the Greek); once of Judas, John 6:70 , who, in his opposition of God, acted the part of the Devil. Apart from John 6:70 , men are never spoken of as devils. It is always to be distinguished from daimon, "a demon." It is found three times, 1—Timothy 3:11; 2—Timothy 3:3; Titus 2:3 , of false accusers, slanderers.

2: κατήγορος
(Strong's #2725 — Noun Masculine — kategoros — kat-ay'-gor-os )

"an accuser," (see ACCUSATION , ACCUSED, B. 4.) is used in John 8:10; Acts 23:30,35; 24:8; 25:16,18 . In Revelation 12:10 , it is used of Satan. In the Sept., Proverbs 18:17 .

Ecclesiastes 5:77:8Psalm 119:134Amos 2:8Psalm 72:4Proverbs 28:16