Definition of mushroomed:
(n) :
Any of the fleshy fruiting bodies of fungi typically produced above ground on soil or on their food sources (such as decaying wood).
(n) :
A fungus producing such fruiting bodies.
(n) :
Champignon or Agaricus bisporus, the mushroom species most commonly used in cooking.
(n) :
(figurative) Something that grows very quickly or seems to appear suddenly.
(v) :
(intransitive, figurative) To grow quickly to a large size or rapidly increase in scope or scale.
(n) :
(architecture) A concrete column with a thickened portion at the top, used to support a slab.