Hotbed
WordNet
noun
(1) A bed of earth covered with glass and heated by rotting manure to promote the growth of plants
(2) A situation that is ideal for rapid development (especially of something bad)
"It was a hotbed of vice"
WiktionaryText
Noun
- a low bed of earth covered with glass, and heated with rotting manure; used for the germination of seeds and the growth of tender plants. A hotbed works as a miniature hothouse, i.e. greenhouse.
- an environment that is ideal for the growth or development of something, especially of something undesirable