noun
or hog-nosed snake
: any of certain moderate-sized stout-bodied No. American snakes that constitute the genus Heterodon, are perfectly harmless though often reputed deadly prob. because of the threatening way in which they dilate the neck, flatten the head, and hiss and blow when startled, and are noted for the habit of rolling over on the back and playing dead when their threatening display is ineffective — called also blowing adder, flatheaded adder, puffing adder, sand viper, spreading adder