noun
toadstool
TOHD-stool/ˈtəʊdstuːl/
A mushroom, especially one thought poisonous or inedible.
The red-capped toadstool grows among moss and fallen leaves.

Etymology
The name apparently imagines a mushroom as a toad's seat; toads themselves were thought highly poisonous. Originally used for umbrella-shaped fungi generally, it later became especially associated with poisonous or inedible kinds.
More examples
- The illustration showed a cluster of toadstools on the forest floor.
- The child pointed to a small toadstool after the rain.
- The guide warned against assuming a toadstool was safe to eat.
Forms
toadstool · toadstools
Similar words
- mushroom
- Mushroom is the broad familiar term; toadstool often implies an inedible or poisonous kind, but is not a reliable safety category.