Leviathan in Fausset's Bible Dictionary

From lewy "joined" (referring to its joined, plate armour like scales) and than a monster drawn out, i.e. long; or else Arabic lavah "to twist." So Job 41:15-17. The crocodile. The whale having a smooth skin and no scales cannot be meant. The crocodile's teeth, 30 on each side of each jaw, lock into each other. Lips are wanting, so that the teeth are seen even when the mouth is closed, illustrating Job 41:14, "who can open the doors of his face? his teeth are terrible round about." As behemoth is the hippopotamus, so leviathan is the crocodile, both found in Egypt along the Nile. The term elsewhere is used for any large monster of the "sea" or water. Psalm 104:26; Psalm 74:13-14; "Thou breakest the heads of leviathan in pieces, and gavest him to be meat to the people inhabiting the wilderness." The king of Egypt is symbolized by the "dragons" and "leviathan" (compare Ezekiel 32:2; Ezekiel 29:3); he and his host at their overthrow in the Red Sea became a spoil to Israel (compare "bread for us," Numbers 14:9) "in the wilderness." The context shows that it is the benefits of God to Israel that are here recounted. In Job 3:8 translated "let them curse it (my day of birth) ... who are ready to raise up a leviathan," i.e. necromancers who rouse and control wild beasts at will (compare Psalm 58:5). In Isaiah 27:1, "leviathan the piercing serpent, even leviathan that crooked (wriggling) serpent," "the dragon in the sea," literally refers to the crocodile in the sea or Nile, or else to the great rock snakes. Spiritually every foe of Israel and the church. Antitypically and finally Satan "the dragon, that old serpent, which is the devil" (Revelation 20:2; Revelation 20:10), whom finally "Jehovah with His sore, great, and strong sword shall punish." For" piercing" (bariach) translated "darting from side to side." Foiled on one side he tries to gain on the other side (Job 26:13; 2 Corinthians 11:14; 2 Corinthians 2:11). Typhon, the destroyer, was worshipped in Egypt under the form of a crocodile.