mycelium

American  

[mahy-see-lee-uhm] / maɪˈsi li əm /

noun

Mycology.

plural

mycelia

1. the mass of hyphae that form the vegetative part of a fungus.

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mycelium British  

/ ˈmaɪsɪˌlɔɪd, maɪˈsiːlɪəm /

noun

1. the vegetative body of fungi: a mass of branching filaments (hyphae) that spread throughout the nutrient substratum

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mycelium Scientific  

/ mī-sē′lē-əm /

plural

mycelia

1. The mass of fine branching tubes (known as hyphae) that forms the main growing structure of a fungus. Visible structures like mushrooms are reproductive structures produced by the mycelium.

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Other Word Forms

• mycelial adjective
• myceloid adjective

Etymology

Origin of mycelium

1830–40; < New Latin, equivalent to Greek myk- myc- + ( h ) ḗl ( os ) wart, nail + New Latin -ium -ium

Example Sentences

Feeding on the waste, the mycelium grows into the desired shape.

From Barron's • Nov. 13, 2025

These are placed into moulds, where mycelium, the root-like structure of fungi, takes over.

From Barron's • Nov. 13, 2025

They included a structure grown from mycelium, the root network of fungus.

From BBC • Sep. 29, 2025

When Stamets talks about mushrooms, or is photographed with mushrooms, they’re typically toadstools, but he also points to evidence indicating that mycelium has higher overall levels of active ingredients than the fruiting bodies.

From Los Angeles Times • Jun. 18, 2025

Most of it is underground, consisting of a network of microscopic cells called mycelium.

From "The Omnivore's Dilemma" by Michael Pollan