'Behemoth' definitions:

Definition of 'behemoth'

noun

Someone or something that is abnormally large and powerful [syn: giant, goliath, behemoth, monster, colossus]

noun

A person of exceptional importance and reputation [syn: colossus, behemoth, giant, heavyweight, titan]

From: GCIDE

Behemoth \Be"he*moth\, n. [Heb. behem[=o]th, fr. Egyptian P-ehe-maut hippopotamus.]
1. An animal, probably the hippopotamus, described in --Job xl. 15-24. [1913 Webster]
2. something of large size or great power. [PJC] Behen

Behemoth (Job 40:15-24). Some have supposed this to be an Egyptian word meaning a "water-ox." The Revised Version has here in the margin "hippopotamus," which is probably the correct rendering of the word. The word occurs frequently in Scripture, but, except here, always as a common name, and translated "beast" or "cattle."