The Greek form, rendered "devil" in the Authorized Version of the New Testament. Daemons are spoken of as spiritual beings (Matt. 8:16; 10:1; 12:43-45) at enmity with God, and as having a certain power over man (James 2:19; Rev. 16:14). They recognize our Lord as the Son of God (Matt. 8:20; Luke 4:41). They belong to the number of those angels that "kept not their first estate," "unclean spirits," "fallen angels," the angels of the devil (Matt. 25:41; Rev. 12:7-9). They are the "principalities and powers" against which we must "wrestle" (Eph. 6:12).
Easton's Bible Dictionary. M.G. Easton. 1897.