fungus

American  

[fuhng-guhs] / ˈfʌŋ gəs /

noun

plural

fungi, funguses

1. any of a diverse group of eukaryotic single-celled or multinucleate organisms that live by decomposing and absorbing the organic material in which they grow, comprising the mushrooms, molds, mildews, smuts, rusts, and yeasts, and classified in the kingdom Fungi or, in some classification systems, in the division Fungi (Thallophyta) of the kingdom Plantae.

2. Pathology. a spongy, abnormal growth, as granulation tissue formed in a wound.

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adjective

1. fungal.

   a fungus infection of the toenails.

fungus British  

/ ˈfʌŋɡəs, ˈfʌndʒɪk /

noun

1. any member of a kingdom of organisms (Fungi) that lack chlorophyll, leaves, true stems, and roots, reproduce by spores, and live as saprotrophs or parasites. The group includes moulds, mildews, rusts, yeasts, and mushrooms

2. something resembling a fungus, esp in suddenly growing and spreading rapidly

3. pathol any soft tumorous growth

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fungus Scientific  

/ fŭng′gəs /

plural

fungi

1. Any of a wide variety of organisms that reproduce by spores, including the mushrooms, molds, yeasts, and mildews. The spores of most fungi grow a network of slender tubes called hyphae that spread into and feed off of dead organic matter or living organisms. Fungi absorb food by excreting enzymes that break down complex substances into molecules that can be absorbed into the hyphae. The hyphae also produce reproductive structures, such as mushrooms and other growths. Some fungi (called perfect fungi) can reproduce by both sexually produced spores and asexual spores; other fungi (called imperfect fungi or deuteromycetes) are thought to have lost their sexual stage and can only reproduce by asexual spores. Fungi can live in a wide variety of environments, and fungal spores can survive extreme temperatures. Fungi exist in over 100,000 species, nearly all of which live on land. They can be extremely destructive, feeding on almost any kind of material and causing food spoilage and many plant diseases. Although fungi were once grouped with plants, they are now considered a separate kingdom in taxonomy.

2. See Table at taxonomy

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Other Word Forms

• fungic adjective
• fungus-like adjective
• funguslike adjective

Etymology

Origin of fungus

First recorded in 1520–30; from Latin: “fungus, mushroom”; perhaps akin to Greek spóngos, sphóngos sponge

Explanation

Is there a fungus among us? A fungus is a simple organism that's not an animal or a plant. A delicious mushroom is one kind of fungus, while another type of fungus causes nasty infections. The plural of fungus is fungi, so when you order a pizza you can request it "with extra fungi" if you like. Mold, yeast, and mildew are all types of fungi, and there are plenty of edible fungi as well, including truffles and portobello mushrooms. While a fungus may look like a plant, it doesn't go through photosynthesis like plants do and it reproduces through spores.

Example Sentences

I can’t speak to the medicinal benefits of snow fungus tea.

From Los Angeles Times • Apr. 6, 2026

They also questioned whether ethanol released through the barrels of whisky could cause the fungus black mould to appear.

From BBC • Mar. 26, 2026

Researchers at Yokohama National University in Japan have identified a previously unknown species of marine fungus capable of killing harmful algae that form toxic blooms.

From Science Daily • Mar. 6, 2026

But he also says the taste is on another level, with the fungus providing an umami-like richness that complements the chocolate.

From MarketWatch • Jan. 27, 2026

She envisioned Grover, bloated, somersaulting in the water, his eyes spongy with fungus ..

From "Typical American" by Gish Jen

Related Words

• affliction
• canker
• decay
• eyesore
• infestation
• mildew
• pest
• scourge