behemoth

From Middle English behemoth, bemoth, from Late Latin behemoth, from Hebrew בְּהֵמוֹת (behemót). Most likely, the Hebrew word is an intensive plural of בְּהֵמָה (behemá, “beast”), from Proto-Semitic (compare Ge'ez ብህመ (bəhmä, “to be dumb, to be speechless”), Arabic ب ه م (b h m)). Some have instead suggested a borrowing from a hypothetical Egyptian pA-i-H-E1-mw (*pꜣ-jḥ-mw, “hippopotamus”, literally “the ox of the water”), from pꜣ (“definite article”) + jḥ (“ox, cattle”) + mw (“water”) in a direct genitive construction (for the pronunciation, compare the later Coptic descendants ⲡ- (p-) + ⲉϩⲉ (ehe) + ⲙⲟⲟⲩ (moou)); this, however, suffers from problems such as the lack of attestation of the supposed etymon, and there seems little reason to prefer it to the intensive plural explanation.

来源：wiktionary