scum

Blue-green algae, also known as cynobacteria, produces a layer of scum that sits on the water and is toxic to wildlife.

From BBC ● Aug. 4, 2026

But not long after the job was complete, the paint began to visibly peel, and the gleaming waters promptly refilled with green pond scum.

From Barron's ● Jun. 21, 2026

“I went through four years of hell by this scum that we had to deal with,” Trump said.

From Salon ● Feb. 6, 2025

The sleepless nights made him feel like a scum had settled over his brain.

From Los Angeles Times ● Dec. 12, 2024

His wet feathers stuck to his tiny body and he was covered with a thick white salty scum.

From "The Egypt Game" by Zilpha Keatley Snyder

When this occurs, blue-green algae can form blooms that discolour the water, or produce floating mats or scums on the water's surface.

From BBC ● Sep. 9, 2025

When this occurs, the algae can form blooms that discolour the water or produce floating mats or scums on the water’s surface.

From BBC ● Sep. 13, 2024

“You’re in the business of representing scums and trying to make as much money as long as there’s this lapse in the law.”

From Time ● Aug. 6, 2014

Put into a jar some maiden barberries, with a good quantity of salt; tie on a bladder, and when the liquor scums change it.

From The Lady's Own Cookery Book, and New Dinner-Table Directory; In Which will Be Found a Large Collection of Original Receipts. 3rd ed. by Lady Charlotte Campbell Bury

The commonest of these pond scums belong to the genus Spirogyra, and one of these will illustrate the characteristics of the order.

From Elements of Structural and Systematic Botany For High Schools and Elementary College Courses by Douglas Houghton Campbell

A thick mist scummed the windshields as the 39-car motorcade rolled eastward under the grey sky toward Andau, a scant kilometer from the border.

From Time Magazine Archive

On the side table was her after-dinner cup, still full of coffee ... black, scummed with oil droplets, stone-cold.

From Special Delivery by Damon Francis Knight

When it is clear scummed, take it off, and let it cool; then work it with Ale-yest; tun it up, and hang it in a bag, with Ginger, Cinamom, Cloves and Cardamom.

From The Closet of Sir Kenelm Digby Knight Opened by Anne MacDonell

The lake opened out before them, scummed with foam and torn into choppy, white-topped waves among which the logs were tossing.

From The Boss of Wind River by A. M. (Arthur Murray) Chisholm

The pot must be well scummed before the herbs are put in.

From The Cook and Housekeeper's Complete and Universal Dictionary; Including a System of Modern Cookery, in all Its Various Branches, Adapted to the Use of Private Families by Mary Eaton

The mission stories often guide you through a level’s most unique assassinations, which is a nice gift to players who don’t like engaging in the aggressive, save scumming and trial-and-error obsessiveness those never-be-seen challenges require.

From The Verge ● Jan. 27, 2021

Boil all these together, till the scum be boiled in, not scumming it.

From The Closet of Sir Kenelm Digby Knight Opened by Anne MacDonell

"There is a brain that will endure but one scumming."

From The Works of Charles and Mary Lamb — Volume 6 Letters 1821-1842 by Mary Lamb

To every pint of juice, add two pounds of powdered loaf-sugar, boiling and scumming it in the same manner as for any other jam or jelly.

From The Cook and Housekeeper's Complete and Universal Dictionary; Including a System of Modern Cookery, in all Its Various Branches, Adapted to the Use of Private Families by Mary Eaton

The next day boil it gently, scumming it all the while till no more scum riseth; and if you will clarifie the Liquor with a few beaten whites of Eggs, it will be the clearer.

From The Closet of Sir Kenelm Digby Knight Opened by Anne MacDonell