Definition of mycelium
: 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)
Keep scrolling for more
Keep scrolling for more
Keep scrolling for more
Test Your Vocabulary
Slippery Words Quiz—Changing with the Times
- What is an earlier meaning of nice?

Test your visual vocabulary with our 10-question challenge!
TAKE THE QUIZ
A daily challenge for crossword fanatics.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridgedWords at Play
Ask the Editors
Word Games
Slippery Words Quiz—Changing with the Times
Do you know these earlier meanings of words?
Take the quizWords of Snow and Ice Quiz
A selection of words from the chillier parts of t...
Take the quizName That Thing
Test your visual vocabulary with our 10-question ...
Take the quizWord Winder's CrossWinder Play the game
Share mycelium
Time Traveler for mycelium
The first known use of mycelium was in 1836
See more words from the same year