1. (noun) New World vipers with hollow fangs and a heat-sensitive pit on each side of the head

• agkistrodon contortrix
• copperhead
• agkistrodon piscivorus
• cottonmouth
• cottonmouth moccasin
• water moccasin
• bothrops atrops
• fer-de-lance
• rattler
• rattlesnake

1. (noun) New World vipers with hollow fangs and a heat-sensitive pit on each side of the head

• crotalidae
• family crotalidae

1. (noun) New World vipers with hollow fangs and a heat-sensitive pit on each side of the head

• viper