Illustration of water moccasin
- water moccasin 1
water moccasin
noun
1
: a venomous semiaquatic pit viper (Agkistrodon piscivorus) chiefly of the southeastern U.S. that is closely related to the copperhead
called also cottonmouth, cottonmouth moccasin
2
: a harmless American colubrid water snake (genus Nerodia) resembling the true water moccasin
Examples of water moccasin in a Sentence
Recent Examples on the Web
There are only a few species of venomous snakes found in the United States: Rattlesnakes, copperheads, cottonmouths (also known as water moccasins) and coral snakes.
—
Cody Godwin, USA Today, 27 Apr. 2026
In the Southeast, there are several venomous snakes that could potentially cause an injury to a human or pet: three species of rattlesnakes (eastern diamondback, timber, and pygmy), copperhead, cotton mouth (also known as water moccasins), and coral snake, says Maerz.
—Arricca Elin Sansone, Southern Living, 12 Apr. 2026
Cottonmouths, sometimes called water moccasins, are more likely to show up near water like lakes, creeks and ponds.
—Tiffani Jackson, Fort Worth Star-Telegram, 7 Apr. 2026
Also known as a water moccasin, this darkly colored—usually near-black or olive brown—snake isn’t aggressive, but its bite is fatal without rapid administration of an antivenom.
—Owen Clarke, Outside, 19 Sep. 2025
Tennessee's most venomous snake is the cottonmouth, or water moccasin.
—Craig Shoup, Nashville Tennessean, 18 Sep. 2025
Rescuers maneuvering through challenging terrain, high waters and snakes including water moccasins continued their desperate search for the missing, including 10 girls and a counselor from the camp.
—Brit Morse, Fortune, 7 July 2025
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Cody Godwin, USA Today, 27 Apr. 2026
In the Southeast, there are several venomous snakes that could potentially cause an injury to a human or pet: three species of rattlesnakes (eastern diamondback, timber, and pygmy), copperhead, cotton mouth (also known as water moccasins), and coral snake, says Maerz.
—Arricca Elin Sansone, Southern Living, 12 Apr. 2026
Cottonmouths, sometimes called water moccasins, are more likely to show up near water like lakes, creeks and ponds.
—Tiffani Jackson, Fort Worth Star-Telegram, 7 Apr. 2026
Also known as a water moccasin, this darkly colored—usually near-black or olive brown—snake isn’t aggressive, but its bite is fatal without rapid administration of an antivenom.
—Owen Clarke, Outside, 19 Sep. 2025
Tennessee's most venomous snake is the cottonmouth, or water moccasin.
—Craig Shoup, Nashville Tennessean, 18 Sep. 2025
Rescuers maneuvering through challenging terrain, high waters and snakes including water moccasins continued their desperate search for the missing, including 10 girls and a counselor from the camp.
—Brit Morse, Fortune, 7 July 2025
Cite this Entry
“Water moccasin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/water%20moccasin. Accessed 13 May. 2026.
Copy CitationMedical Definition
water moccasin
noun
water moc·ca·sin
-ˌmäk-ə-sən 
: a venomous semiaquatic pit viper (Agkistrodon piscivorus) of the southern United States closely related to the copperhead
called also cottonmouth, cottonmouth moccasin
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