muck

American  

[muhk] / mʌk /

noun

1. moist farmyard dung, decaying vegetable matter, etc.; manure.

2. a highly organic, dark or black soil, less than 50 percent combustible, often used as a manure.

3. mire; mud.

4. filth, dirt, or slime.

5. defamatory or sullying remarks.

6. a state of chaos or confusion.

   to make a muck of things.

7. Chiefly British Informal. something of no value; trash.

8. (especially in mining) earth, rock, or other useless matter to be removed in order to get out the mineral or other substances sought.

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verb (used with object)

1. to manure.

2. to make dirty; soil.

3. to remove muck from (sometimes followed byout ).

4. Informal.

   1. to ruin; bungle (often followed byup ).

   2. to put into a state of complete confusion (often followed byup ).

verb phrase

1. muck about / around to idle; waste time; loiter.

muck British  

/ mʌk /

noun

1. farmyard dung or decaying vegetable matter

2. Also called: muck soil.  an organic soil rich in humus and used as a fertilizer

3. dirt or filth

4. earth, rock material, etc, removed during mining excavations

5. slang rubbish

6. See Lord Muck Lady Muck

7. slang to ruin or spoil

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verb

1. to spread manure upon (fields, gardens, etc)

2. to soil or pollute

3. (often foll by out) to clear muck from

Etymology

Origin of muck

1200–50; Middle English muc, muk < Old Norse myki cow dung

Explanation

Muck is a goopy, muddy substance, like the muck at the bottom of a pond or the muck you clean out of the gutters on your house once a year. You can also use muck to mean animal manure, its original, 13th-century meaning — specifically, "cow dung and vegetable matter used as manure." The definition has expanded since then to include any number of dirty, slimy substances, from the mud on the bottom of a lake to the sludge in a flooded basement. As a verb, to muck is either to remove animal waste or to spread manure on a field.

Example Sentences

Three quarters of public relations pros surveyed by Muck Rack External link say they use AI on the job, with editing and writing among the most frequent uses and greatest timesavers.

From Barron's • Apr. 14, 2026

Indeed, the Muck Rack data estimate that less than 30,000 individuals have posted over 50,000 times with mentions and hashtags like #taxstrike.

From MarketWatch • Apr. 6, 2026

When we’re sleep-deprived, our brains react more slowly, explains Muck.

From Slate • Nov. 26, 2025

Open Seas describes the area around Canna, Eigg, Muck and Rum as some of the most biodiverse seas in Scotland.

From BBC • Sep. 23, 2024

I’ll get you later, she says, I’ll warm your arse, and you, Lord Muck, she says to me, put that child down on the floor over there by the range.

From "Angela's Ashes: A Memoir" by Frank McCourt

Related Words

• dirt
• goo
• gunk
• manure
• mud
• slime
• sludge
• trash