Definition from Wiktionary, the free dictionary
hotbed (plural hotbeds)
- 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.
- (by extension) an environment that is ideal for the growth or development of something, especially of something undesirable
a low bed of earth covered with glass