Lexical Definition

‎לִוְיָתָן‎ livyâthân (liv-yaw-thawn') Leviathan ^N:N-M-T
from ‎לָוָה‎

leviathan, mourning.

• a wreathed animal, i.e. a serpent (especially the crocodile or some other large sea-monster)
• figuratively, the constellation of the dragon
• also as a symbol of Babylon

1) leviathan, sea monster, dragon
1a) large aquatic animal
1b) perhaps the extinct dinosaur, plesiosaurus, exact meaning unknown
++++
Some think this to be a crocodile but from the description in Job 41:1-34 this is patently absurd. It appears to ba a large fire breathing animal of some sort. Just as the bomardier beetle has an explosion producing mechanism, so the great sea dragon may have an explosive producing mechanism to enable it to be a real fire breathing dragon.

See Greek: δράκων · κῆτος · μέγας

Extended Information

• a sea monster, dragon

Brown-Driver-Briggs

‎לִוְיָתָן‎ noun masculine^{Job 40:25*} serpent, dragon, leviathan, in poetry and rare (on formation from ‎לוה‎ with feminine ‎ת‎+ ‎ןָ֯‎ see Thes and compare Ges^{«GKC:85»§ 85}, 54 Kö^{ii, p. 99} Ba^{NB § 207c}; Lag^{BN 205} thinks foreign loan-word); — sea-monster = crocodile Job 40:25* whale Ps 104:25 (see Che); dragon producing eclipses (mythological) Job 3:8 figurative of Egypt as all-engulfing Ps 74:14 (|| ‎תַּנִּינִים‎ vPs 74:13); compare Isa 27:1 (twice in verse) (|| ‎נָחָשׁ בָּרִחַ‎, ‎נָחָשׁ עֲקַלָּתוֺן‎), see Che Di and especially (on ‎׳‎‎ל‎ in general) Barton^{Tiamat, JAOS xv (1891), 22 ff.} Gunk^{Schöpf. u. Chaos 46}.

Brown-Driver-Briggs References