Generally supposed to be related to the cobra. The same word is also given as “adder” (Ps. 58:4; 91:13).
Dragons.
The word thus translated is from the root “to stretch out,”“to extend.” The literal meaning of the derived noun is “the extended ones,” in reference to body length. Elsewhere it appears as “whales” (Gen. 1:21), “serpent” (Ex. 7:9, 10, 12), “sea monsters” (Lam. 4:3).