Nouns

(n)mushroomcommon name for an edible agaric (contrasting with the inedible toadstool)
(n)mushroommushrooms and related fleshy fungi (including toadstools, puffballs, morels, coral fungi, etc.)
(n)mushroomany of various fleshy fungi of the subdivision Basidiomycota consisting of a cap at the end of a stem arising from an underground mycelium
(n)mushroom, mushroom cloud, mushroom-shaped clouda large cloud of rubble and dust shaped like a mushroom and rising into the sky after an explosion (especially of a nuclear bomb)
(n)mushroomfleshy body of any of numerous edible fungi

Verbs

(v)mushroompick or gather mushrooms“We went mushrooming in the Fall”
(v)mushroomgrow and spread fast“The problem mushroomed”