Meaning

noun a gelatinous substance secreted by plants

noun cement consisting of a sticky substance that is used as an adhesive

originFrom Middle English muscilage, mussillage, from Middle French mucilage (“viscous substance found in vegetable material”), from Late Latin mūcilāgō (“musty or moldy juice”). See Greek μούχλα (moúchla, “mold”), and related derivatives, for example mushroom, from *meus- (“mosses, mold, mildew”).

Etymology from Wiktionary, CC BY-SA 3.0