Easton's Bible Dictionary (1897)/Dragon
Dragon:
(1.) Heb.@tannim, plural of tan. The name of some unknown creature inhabiting desert places and ruins (Job 30:29; Ps. 44:19; Isa. 13:22; 34:13; 43:20; Jer. 10:22; Micah 1:8; Mal. 1:3); probably, as translated in the Revised Version, the jackal (q.v.).
(2.) Heb.@tannin. Some great sea monster (Jer. 51:34). In Isa. 51:9 it may denote the crocodile. In Gen. 1:21 (Heb.@plural tanninim) the Authorized Version renders "whales," and the Revised Version "sea monsters." It is rendered "serpent" in Ex. 7:9. It is used figuratively in Ps. 74:13; Ezek. 29:3.
In the New Testament the word "dragon" is found only in Rev. 12:3, 4, 7, 9, 16, 17, etc., and is there used metaphorically of "Satan." (See WHALE.)