mushroom
nounUK /ˈmʌʃ.ruːm/
US /ˈmʌʃ.rʊm/
A mushroom is a small plant-like thing with a round top and a stem that grows in wet places.
We found a big mushroom under the tree.
OTHER MEANINGS
2. To grow or increase very quickly.
New shops mushroomed all over the town.
3. The fast-growing part of a fungus that we can see above the ground.
The mushroom popped up after the rain.
4. A cloud shaped like a mushroom, made by a big explosion.
A mushroom cloud rose into the sky.