fungus

noun

fun·​gus ˈfəŋ-gəs 

plural fungi ˈfən-ˌjī  ˈfəŋ-ˌgī  also funguses ˈfəŋ-gə-səz 

often attributive

: any of a kingdom (Fungi) of saprophytic and parasitic spore-producing eukaryotic typically filamentous organisms formerly classified as plants that lack chlorophyll and include molds, rusts, mildews, smuts, mushrooms, and yeasts

Examples of fungus in a Sentence

Recent Examples on the Web

The researchers grew mycelium from the fungus Neurospora crassa, commonly known as red bread mold, into a dense, scaffold-like structure. —Margherita Bassi, Smithsonian Magazine, 24 Apr. 2025

From a technical point of view, brewer’s yeast is a collection of microscopic, nonpathogenic unicellular fungi known by the scientific name saccharomyces cerevisiae, which can be used in an active or inactive form. —Beatrice Zocchi, Vogue, 16 Apr. 2025

While fungi are pivotal for biodiversity and ecosystem health, their role in the carbon cycle inserts additional urgency to their conservation needs. —The Editors, JSTOR Daily, 16 Apr. 2025

In a scene set in 1968, a scientist explained that his greatest fear was that a warming planet would provide the perfect incubating conditions for a mind-controlling fungus that could turn humans into brainless killers. —Noel Murray, New York Times, 14 Apr. 2025

Word History

Etymology

Latin

First Known Use

1527, in the meaning defined above

Phrases Containing fungus

• bracket fungus
• chytrid fungus
• club fungus
• cup fungus
• fungus gnat
• imperfect fungus
• lower fungus
• pore fungus
• sac fungus
• shelf fungus

Rhymes for fungus

• fungous
• tungus

Kids Definition

fungus

noun

fun·​gus ˈfəŋ-gəs 

plural fungi ˈfən-ˌjī  ˈfəŋ-ˌgī  also funguses

1

: any of a kingdom of living things (as molds, rusts, mildews, smuts, and mushrooms) that lack chlorophyll, are parasitic or live on dead or decaying organic matter, and were formerly considered plants

2

: infection with a fungus

fungus adjective

Medical Definition

fungus

noun

fun·​gus ˈfəŋ-gəs 

plural fungi

ˈfən-ˌjī also ˈfəŋ-ˌgī

also funguses ˈfəŋ-gə-səz 

often attributive

1

: any of the kingdom Fungi of saprophytic and parasitic spore-producing eukaryotic typically filamentous organisms formerly classified as plants that lack chlorophyll and include molds, rusts, mildews, smuts, mushrooms, and yeasts

2

: infection with a fungus