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 evolution of land plants and the development of soil go hand in hand—as these pioneering plants, trees, and animals died and their decomposing remains were recycled on land, by fungi and the first soil invertebrates, modern soils began to form. — Literary Hub, 2 Oct. 2026

To combat this issue, trim phlox plants in the fall and carefully dispose of any diseased leaves, either by burning or bagging them for trash disposal to prevent spreading the fungus. — Lauren Landers, Better Homes & Gardens, 28 Sep. 2026

Without microbes, such as bacteria, fungi, protozoa, and other microorganisms, plant growth will suffer, as these microorganisms break down material that then feeds your plants or grass. — Michelle Mastro, Martha Stewart, 26 Sep. 2026

The interiors feature Borneo ironwood, valued for its resistance to termites, rot, and fungi, with about 90 percent of the wood being reclaimed. — Tori Latham, Robb Report, 25 Sep. 2026

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