8 letters · 17 points in Scrabble
noun the vegetative part of a fungus consisting of a mass of branching threadlike hyphae
originFrom New Latin mycelium; synchronically, myc- + -el- + -ium, where the infix -el- is of unknown origin, perhaps introduced from a rebracketing of epithelium.
Etymology from Wiktionary, CC BY-SA 3.0