pit viper

American  

noun

1. any of numerous venomous snakes of the family Crotalidae, of the New World, Asia, and the Malay Archipelago, as the rattlesnake, water moccasin, and copperhead, having a heat-sensitive pit on each side of the head between the eye and nostril.

---

pit viper British  

noun

1. any venomous snake of the New World family Crotalidae, having a heat-sensitive organ in a pit on each side of the head: includes the rattlesnakes

---

pit viper Scientific  

1. Any of various very venomous snakes of the family Crotalidae. Pit vipers are characterized by a triangular head with a small sensory pit below each eye. The pits detect infrared radiation and help the snake locate prey. Some scientists classify the pit vipers as a subfamily Crotalinae within the Viperidae, the family of vipers, rather than as a separate family. Copperheads, rattlesnakes, and fer-de-lances are pit vipers.

---

Etymology

Origin of pit viper

First recorded in 1880–85

Example Sentences

In 2019, officials at the Chennai airport seized a horned pit viper snake, five Iguanas, four blue-tongued skinks, three green tree frogs and 22 Egyptian tortoises from a man travelling from Thailand.

From BBC • Jun. 2, 2025

I had to stare hard to spot a lime-green pit viper camouflaged on a twig beside the trail.

From National Geographic • Jan. 23, 2024

However, some populations of the new species are bright green with no blotches and look virtually identical to the redtail pit viper.

From Science Daily • Dec. 21, 2023

The institute produced more than 3,000 vials of antivenom targeting five species, including the hump-nosed pit viper.

From Scientific American • Sep. 23, 2023

Ned would sooner entrust a child to a pit viper than to Lord Tywin, but he left his doubts unspoken.

From "A Game of Thrones" by George R.R. Martin