mushroom cloud

Mushroom Mush"room, a. 1. Of or pertaining to mushrooms; as, mushroom catchup. [1913 Webster]

2. Resembling mushrooms in rapidity of growth and shortness of duration; short-lived; ephemerial; as, mushroom cities. [1913 Webster]

{Mushroom anchor}, an anchor shaped like a mushroom, capable of grasping the ground in whatever way it falls.

{Mushroom coral} (Zo["o]l.), any coral of the genus {Fungia}. See {Fungia}.

{Mushroom spawn} (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.

{mushroom cloud}, 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. [1913 Webster +PJC]