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

Beneath the mushroom, mostly invisible to us, is an underground structure: the mycelium. —Skye Chilton, Rolling Stone, 16 June 2025

The mushrooms are cultivated using solid-state fermentation, a process in which the mycelium feeds on gluten-free organic oats and transforms them into bioavailable nutrients. —Boutayna Chokrane, Wired News, 6 June 2025

For this work, the researchers chose a particular strain of the split-gill mushroom – which typically grows on dead wood – and used the entire fungus rather than just the root-like mycelium. —Abhimanyu Ghoshal, New Atlas, 16 May 2025

For example, products made with mycelium benefit the planet as a whole and not just the people who use the products. —Eva Amsen, Forbes.com, 11 July 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)