תְּהוֹם tehom "the deep". Either the primeval waters under the earth, or sea as opposite of sky. In Gen 7:11 the "great deep" is a source for Noah's flood; while Is 51:10 describes God drying up the great deep so making "a way for the redeemed to cross over". In Amos 7:4 by contrast, the drying is a severe punishment.