compost

American  

[kom-pohst] / ˈkɒm poʊst /

noun

1. a mixture of various decaying organic substances, as dead leaves or manure, used for fertilizing soil.

2. a composition; compound.

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verb (used with object)

1. to use in compost; make compost of.

   to compost manure and kitchen scraps.

2. to apply compost to (soil).

verb (used without object)

1. to make compost.

   Shredded leaves will compost easily.

compost British  

/ ˈkɒmpɒst /

noun

1. a mixture of organic residues such as decomposed vegetation, manure, etc, used as a fertilizer

2. a mixture, normally of plant remains, peat, charcoal, etc, in which plants are grown, esp in pots

3. rare a compound or mixture

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verb

1. to make (vegetable matter) into compost

2. to fertilize with compost

compost Scientific  

/ kŏm′pōst′ /

1. A mixture of decayed or decaying organic matter used to fertilize soil. Compost is usually made by gathering plant material, such as leaves, grass clippings, and vegetable peels, into a pile or bin and letting it decompose as a result of the action of aerobic bacteria, fungi, and other organisms.

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Other Word Forms

• compostable adjective
• composter noun

Etymology

Origin of compost

1350–1400; Middle English < Anglo-French, Middle French < Latin compositum, noun use of neuter of compositus composite; compote

Explanation

Compost is organic matter like orange peels and coffee grounds mixed together and left to decay, usually in a compost pile, then used as fertilizer. To make such a mixture is to compost. To compost is to make a mixture of organic matter, such as manure and leftover food, and leave it somewhere like a compost pile in the back yard or in a bucket with a tight lid in the kitchen. The mixture is also called compost, and after it sits and decays for a while, voila! It turns into fertilizer that makes the soil rich and the plants happy.

Example Sentences

In a space mission setting, the worms could generate compost from discarded materials such as food scraps or cotton clothing and hygiene products that would otherwise be thrown away.

From Science Daily • Mar. 12, 2026

Patrick mows the grass in the garden and puts the cuttings on the compost heap.

From BBC • Mar. 7, 2026

Microbes break down everything but bones, which are ground into the final compost mix.

From The Wall Street Journal • Feb. 3, 2026

But coyotes aren’t picky: They will eat what’s available including rabbits, raccoons, birds, insects, fruit, vegetables, the contents of your garbage or compost, outdoor pet food and small pets.

From Los Angeles Times • Jan. 8, 2026

“Dr. P and I are starting a neighborhood compost project.”

From "Keeping Pace" by Laurie Morrison

Related Words

• fertilizer