n. The vegetative part of any fungus, consisting of a mass of branching, threadlike hyphae, often underground.
the GNU version of the Collaborative International Dictionary of English
n. The white threads or filamentous growth from which a mushroom or fungus is developed; the so-called mushroom spawn.
The Century Dictionary and Cyclopedia
n. The vegetative part of the thallus of fungi, composed of one or more hyphæ.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. the vegetative part of a fungus consisting of a mass of branching threadlike hyphae
Word Usage
"We have now discovered that there is a multi-directional transfer of nutrients between plants, mitigated by the mcyelium -- so the mycelium is the mother that is giving nutrients from alder and birch trees to hemlocks, cedars and Douglas firs."