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scum

American  
[skuhm] / skʌm /

noun

  • scums
    plural
  1. a film or layer of foul or extraneous matter that forms on the surface of a liquid.

  2. refuse or offscourings.

  3. a low, worthless, or evil person.

  4. such persons collectively; riffraff; dregs.

  5. scoria.


verb (used with object)

  • scums,
    present (3rd person singular)
  • scummed,
    past participle,  past
  • scumming
    present participle
  1. to remove the scum from.

  2. to remove as scum.

verb (used without object)

  • scums,
    present (3rd person singular)
  • scummed,
    past participle,  past
  • scumming
    present participle
  1. to form scum; become covered with scum.

scum British  
/ skʌm /

noun

  1. a layer of impure matter that forms on the surface of a liquid, often as the result of boiling or fermentation

  2. the greenish film of algae and similar vegetation surface of a stagnant pond

  3. Also called: dross.   scruff.  the skin of oxides or impurities on the surface of a molten metal

  4. waste matter

  5. a worthless person or group of people

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

verb

  1. (tr) to remove scum from

  2. rare (intr) to form a layer of or become covered with scum

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Derived Forms

Inflected Forms

Nouns

Participles

Conjugated Forms

Present

Past

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Etymology

Origin of scum

1200–50; Middle English scume < Middle Dutch schūme ( Dutch schuim ) foam; cognate with German Schaum foam

Vocabulary lists containing scum

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

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

While Embo didn’t have much screen time, he can be glimpsed among the scum and villainy in a handful of episodes including Season 2 Episode 17, Season 5 Episode 14 and Season 6 Episode 5.

From Los Angeles Times May 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

Pyongyang has denounced him as "human scum" and accused him of embezzling state funds and other crimes.

From BBC Jul. 18, 2024

It was easy to tell who had availed themselves of the baths drawn for them, because their tubs were coated in the brown scum of weeks of unwash.

From "Strange the Dreamer" by Laini Taylor

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

Mixing of filter press scums with diffusion juices is said to offer special advantages for the preliminary purification.

From Scientific American Supplement, No. 832, December 12, 1891 by Various

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

Then boil it gently, skimming it all the while, till all the scum be perfectly scummed off; and after that boil it a little longer, peradventure a quarter of an hour.

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

He had spent the night in a foetid cell with a number of other delinquents who had been scummed off the streets.

From A Vendetta of the Desert by W. C. (William Charles) Scully

At the bridge the shingle bank baulks the stream from a clear course into the sea and usually forces it into an ignominious and green scummed pool that slowly filters through the stony wall.

From Wanderings in Wessex An Exploration of the Southern Realm from Itchen to Otter by Edric Holmes

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

"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

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

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

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

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