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le·vi·a·than
ləˈvīəTHən/
noun
(in biblical use) a sea monster, identified in different passages with the whale and the crocodile (e.g., Job 41, Ps. 74:14), and with the Devil (after Isa. 27:1).
a very large aquatic creature, especially a whale.
"the great leviathans of the deep"
a thing that is very large or powerful, especially a ship.