"kind of porridge; meal boiled in water or milk until it forms a thick, soft mass," 1670s, in the American colonies, a variant of mash (n.) "soft mixture." Meaning "anything soft and thick" is attested from 1824.
command to sled dogs, 1897, first recorded 1862, as mouche, perhaps altered from French marchons! "advance!" (imperative of marcher "to march;" see march (v.)). Related: Musher.
breakfast dish of oats, fruit, and nuts, eaten with milk or yogurt, 1926, from Swiss-German, from Old High German muos "meal, mush-like food," from Proto-Germanic *mod-sa-, from PIE root *mad- "moist, wet," with derivatives referring to various qualities of food (see mast (n.2)).
"peas, beans, lentils; the esculent seeds of any leguminous plant," late 13c., puls, from Old French pouls, pous, pols and directly from Latin puls "thick gruel, porridge, mush," which is suspected of being (perhaps via Etruscan), from Greek poltos "porridge" made from flour, or both the Greek and Latin words might be from the same source (compare pollen), which might be a loanword from a non-PIE Mediterranean language or an as-yet-unknown PIE root.
"fallen nuts or acorns serving as food for animals." Old English mæst, the collective name for the fruit of the beech, oak, chestnut, and other forest trees, especially serving as food for swine, from Proto-Germanic *masto (source also of Dutch, Old High German, German mast "mast;" Old English verb mæsten "to fatten, feed"), perhaps from PIE *mad-sta-, from root *mad- "moist, wet," also used of various qualities of food (source also of Sanskrit madati "it bubbles, gladdens," medah "fat, marrow;" Latin madere "be sodden, be drunk;" Middle Persian mast "drunk;" Old English mete "food," Old High German muos "meal, mush-like food," Gothic mats "food").
"expand or increase rapidly; rise suddenly in position or rank," 1741, from mushroom (n.). Related: Mushroomed; mushrooming.
a word applied at first to almost any of the larger fungi but later to the agaricoid fungi and especially the edible varieties, mid-15c., muscheron, musseroun (attested 1327 as a surname, John Mussheron), from Anglo-French musherun, Old French meisseron (11c., Modern French mousseron), perhaps from Late Latin mussirionem (nominative mussirio), though this might as well be borrowed from French.
Barnhart says "of uncertain origin." Klein calls it "a word of pre-Latin origin, used in the North of France;" OED says it usually is held to be a derivative of French mousse "moss" (from Germanic), and Weekley agrees, saying it is properly "applied to variety which grows in moss," but Klein says they have "nothing in common." For the final -m Weekley refers to grogram, vellum, venom. Modern spelling is from 1560s.
Used figuratively for something or someone that makes a sudden appearance in full form from 1590s, especially an upstart person or family, one who rises rapidly from a low station in life. In reference to the shape of clouds that rise upward and outward after explosions, etc., it is attested from 1916, though the actual phrase mushroom cloud does not appear until 1955.