from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun Any of various fungi that produce a fleshy fruiting body, especially one consisting of a stalk with an umbrella-shaped cap.
  • noun Any of such fungi that are edible, especially the widely cultivated species Agaricus bisporus.
  • noun The usually aboveground fruiting body of any of such fungi.
  • noun One of these fruiting bodies that produce hallucinations when ingested.
  • noun Something shaped like one of these fungi.
  • intransitive verb To multiply, grow, or expand rapidly.
  • intransitive verb To swell or spread out into a shape similar to a mushroom.
  • intransitive verb To collect wild mushrooms.
  • adjective Relating to, consisting of, or containing mushrooms.
  • adjective Resembling mushrooms in rapidity of growth or evanescence.

from The Century Dictionary.

  • To spread out at the top in a form resembling that of a mushroom; curve over at the top; curve down from the top like a mushroom.
  • Having the form or shape of a mushroom or toadstool; formed like the segment of a sphere; said of valves, anchors, etc.
  • To elevate suddenly in position or rank.
  • noun A cryptogamic plant of the class Fungi: applied in a general sense to almost any of the larger, conspicuous fungi, such as toadstools, puffballs, Hydnei, etc., but more particularly to the agaricoid fungi and especially to the edible forms.
  • noun An upstart; one who rises rapidly from a low condition in life.
  • noun A small mushroom-shaped protuberance that sometimes forms on the end of the negative carbon in arc-lamps.
  • Of or pertaining to mushrooms; made of mushrooms: as, mushroom sauce.
  • Resembling mushrooms in rapidity of growth and in unsubstantiality; ephemeral; upstart: as, mushroom aristocracy.

from the GNU version of the Collaborative International Dictionary of English.

  • noun An edible fungus (Agaricus campestris), having a white stalk which bears a convex or oven flattish expanded portion called the pileus. This is whitish and silky or somewhat scaly above, and bears on the under side radiating gills which are at first flesh-colored, but gradually become brown. The plant grows in rich pastures and is proverbial for rapidity of growth and shortness of duration. It has a pleasant smell, and is largely used as food. It is also cultivated from spawn.
  • noun Any large fungus developing a visible fruiting body with a stem and cap, usu. of the basidiomycetes
  • noun One who rises suddenly from a low condition in life; an upstart.
  • adjective Of or pertaining to mushrooms.
  • adjective Resembling mushrooms in rapidity of growth and shortness of duration; short-lived; ephemerial.
  • adjective an anchor shaped like a mushroom, capable of grasping the ground in whatever way it falls.
  • adjective (Zoöl.) any coral of the genus Fungia. See Fungia.
  • adjective (Bot.) the mycelium, or primary filamentous growth, of the mushroom; also, cakes of earth and manure containing this growth, which are used for propagation of the mushroom.
  • adjective a cloud of smoke rising and then spreading laterally to take on the shape of a mushroom -- caused by large fires or explosions, esp. nuclear explosions.
  • intransitive verb to grow or expand rapidly.
  • intransitive verb to grow so much and so rapidly as to change qualitatively; used with into.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun Any of the fleshy fruiting bodies of fungi typically produced above ground on soil or on their food sources (such as decaying wood).
  • noun A fungus producing such fruiting bodies.
  • noun champignon or Agaricus bisporus, the mushroom species most commonly used in cooking.
  • noun One of the mushroom-shaped pegs in bar billiards.
  • adjective Containing or being made of mushrooms.
  • adjective Resembling a mushroom by shape or appearance.
  • verb intransitive To grow quickly to a large size.
  • verb To gather mushrooms.
  • verb ballistics (Of a bullet) To form the shape of a mushroom when a bullet impacts a soft target.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a large cloud of rubble and dust shaped like a mushroom and rising into the sky after an explosion (especially of a nuclear bomb)
  • noun fleshy body of any of numerous edible fungi
  • noun any of various fleshy fungi of the subdivision Basidiomycota consisting of a cap at the end of a stem arising from an underground mycelium
  • verb pick or gather mushrooms
  • noun mushrooms and related fleshy fungi (including toadstools, puffballs, morels, coral fungi, etc.)
  • noun common name for an edible agaric (contrasting with the inedible toadstool)
  • verb grow and spread fast


from The American Heritage® Dictionary of the English Language, 4th Edition

[Alteration (influenced by room) of Middle English musheron, from Anglo-Norman moscheron, musherum, from Old French mousseron, from Medieval Latin musariō, musariōn-.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Middle English musheron, musseron, from Anglo-Norman, from Old French mousseron, from Medieval Latin mussiriōnem, musariōnem, accusative of mussiriō, musariō ("mushroom"), of Germanic origin: French mousse ("moss") (—first applied to a type of fungus which grows in moss), from Low Frankish *mosa ("moss") or Old Dutch mosa "moss", akin to Old High German mos ("moss, bog"), Old High German mios ("moss, mire"), Old English mēos ("moss"), Old English mōs ("bog, marsh"), Old Norse mosi ("moss"), Old Norse myrr ("bog, mire"), from Proto-Germanic *musan, *musô, *miuziz (“mosses, bog”), from Proto-Indo-European *meus- (“mosses, mold, mildew”). Replaced native swamm ("mushroom") from Old English. More at mire


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