עֶכֶס, (cmp. עכן; b. h. chain, clasp) adder, viper (believed to kill a flying bird by looking at its shadow). Mekh. B’shall., Vayassʿa, s. 1 (expl. אפעה, Is. XXX, 6); Tanḥ. B’shall. 18; Yalk. Jer. 266.