Wiktionary
death cap
n. The deadly poisonous mushroom ''Amanita phalloides''.
WordNet
death cap
n. extremely poisonous usually white fungus with a prominent cup-shaped base; differs from edible Agaricus only in its white gills [syn: death cup, death angel, destroying angel, Amanita phalloides]
Usage examples of "death cap".
The species, the Death Cap, is the most fatally poisonous of all Fungi, though it has a pleasant taste and smell and looks perfectly harmless.
Cords were strung about the cauldron, over which were draped nightshade, hemlock, rhododendron, savin, bark of the yew tree, and numerous mushrooms, such as death cap and spotted cort, all of which Eragon recognized from Oromis’.