pond scum
noun
1
: any of various algae (especially spirogyra) or cyanobacteria
2
: a mass of tangled filaments of algae or cyanobacteria in stagnant waters
Examples of pond scum in a Sentence
Recent Examples on the Web
Their small bodies are tricky to differentiate from pond scum or sticky clumps of algae in the dark.
—
Sophie Hartley, IndyStar, 9 Sep. 2025
Minnesota This machine, which is hitched to a trailer and taken to a wastewater treatment facility in Rosemount, converts pond scum into biodiesel, at the Biosystems and Agricultural Engineering Building in St. Paul, Minnesota.
—Scott Cohn, CNBC, 22 July 2025
Algae: The Food of the Future of the Past
In the years following World War II, American and European food scientists hoped to feed the world with common pond scum supplemented with plastics.
—JSTOR Daily, 24 June 2024
Yet the evidence for cogitating pond scum grows daily.
—Rowan Jacobsen, Scientific American, 1 Feb. 2024
After a lovely day of rolling in the grass, digging in the dirt, playing in mud or pond scum, bathe your pet with Calm Shampoo, which is a one-of-a-kind day at the spa for Rocco & Roxie Supply Co.'s dogs.
—Amber Smith, Discover Magazine, 22 Oct. 2022
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Sophie Hartley, IndyStar, 9 Sep. 2025
Minnesota This machine, which is hitched to a trailer and taken to a wastewater treatment facility in Rosemount, converts pond scum into biodiesel, at the Biosystems and Agricultural Engineering Building in St. Paul, Minnesota.
—Scott Cohn, CNBC, 22 July 2025
Algae: The Food of the Future of the Past
In the years following World War II, American and European food scientists hoped to feed the world with common pond scum supplemented with plastics.
—JSTOR Daily, 24 June 2024
Yet the evidence for cogitating pond scum grows daily.
—Rowan Jacobsen, Scientific American, 1 Feb. 2024
After a lovely day of rolling in the grass, digging in the dirt, playing in mud or pond scum, bathe your pet with Calm Shampoo, which is a one-of-a-kind day at the spa for Rocco & Roxie Supply Co.'s dogs.
—Amber Smith, Discover Magazine, 22 Oct. 2022
Cite this Entry
“Pond scum.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/pond%20scum. Accessed 16 Sep. 2025.
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