mushroom-shaped cloud(n = noun.phenomenon) mushroom, mushroom cloud - a large cloud of rubble and dust shaped like a mushroom and rising into the sky after an explosion (especially of a nuclear bomb);
is a kind of cloud

altocumulus cloud, altostratus cloud, be on cloud nine, cirrocumulus cloud, cirrostratus cloud, cirrus cloud, cloud, cloud bank, cloud chamber, cloud cover, cloud grass, cloud nine, cloud over, cloud seeder, cloud up, cumulonimbus cloud, cumulus cloud, dark cloud, dust cloud, large magellanic cloud, magellanic cloud, mother-of-pearl cloud, mushroom cloud, mushroom-shaped, nacreous cloud, nimbus cloud, oort cloud, rain cloud, red cloud, saint cloud, small magellanic cloud, st. cloud, storm cloud, stratus cloud, war cloud, wilson cloud chamber