mycelium

noun

my·​ce·​li·​um mī-ˈsē-lē-əm 

plural mycelia mī-ˈsē-lē-ə 

: the mass of interwoven filamentous hyphae that forms especially the vegetative portion of the thallus of a fungus and is often submerged in another body (as of soil or organic matter or the tissues of a host)

also : a similar mass of filaments formed by some bacteria (such as streptomyces)

mycelial

mī-ˈsē-lē-əl 

adjective

Examples of mycelium in a Sentence

Recent Examples on the Web

Under an inflatable shell, they would be made of mycelium, a root-like fungal structure, something of an alternative building material heroine, lauded for its durability; versatility; and water-, mold-, and fire-resistant properties. —Elizabeth Fazzare, Architectural Digest, 25 June 2025

Firstly, that mushrooms do not contain starch, but supplements consisting of mycelium grown on grain does. —Mattha Busby, Los Angeles Times, 18 June 2025

Unlike many mushroom supplements that focus on extracts or isolated compounds, Om’s Master Blend utilizes the entire mushroom: mycelium, primordia, and fruiting body. —Boutayna Chokrane, Wired News, 6 June 2025

Researchers in Montana grew a framework for a living, self-repairing building material from mycelium, or the rootlike structures that connect fungal networks, and it could eventually be used to build homes in the future. —Ashley Strickland, CNN Money, 4 May 2025

Word History

Etymology

borrowed from New Latin, from myc- (from base of Greek mykēt-, mýkēs "mushroom, fungus") + -el- (of unknown origin) + -ium -ium — more at myco-

Note: Term introduced by the Austrian botanist and mycologist Leopold Trattinnick (1764-1849) in Fungi Austriaci, ad specimina viva cera expressi descriptiones ac historiam naturalem completam addidit Leopoldus Trattinnick/Oesterreichs Schwämme, nach lebendigen Originalen in Wachs gearbeitet mit Beschreibungen und einer ausführlichen Naturgeschichte, 1. Lieferung (Vienna, 1804). Trattinnick, who uses the word throughout the work, gives no indication of its derivation. His translation in the parallel vernacular columns is Schwammgewächs, literally, "mushroom growth." The reading of -el- as Greek hêlos "nail head, wart, callus," apparently first proposed in the Century Dictionary and copied by many dictionaries since, is improbable and in any case purely speculative. Somewhat more probable is the suggestion in the Oxford English Dictionary that the interposed -l- is after epithelium.

First Known Use

1836, in the meaning defined above

Rhymes for mycelium

• athenaeum
• coliseum
• colosseum
• mausoleum
• corneum
• hordeum
• luteum
• lyceum
• museum
• endothelium
• periosteum
• peritoneum

Kids Definition

mycelium

noun

my·​ce·​li·​um mī-ˈsē-lē-əm 

plural mycelia

-lē-ə

: the part of the body of a fungus that does not reproduce and usually consists of a mass of hyphae that are often growing in something else (as soil, organic matter, or the tissues of a plant or animal host)

mycelial

-lē-əl 

adjective

Medical Definition

mycelium

noun

my·​ce·​li·​um mī-ˈsē-lē-əm 

plural mycelia -lē-ə 

: the mass of interwoven filamentous hyphae that forms especially the vegetative body of a fungus and is often submerged in another body (as of soil or organic matter or the tissues of a host)

also : a similar mass of filaments formed by some bacteria (as of the genus Streptomyces)