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
emphasis If you say that somewhere is a hotbed of an undesirable activity, you are emphasizing that a lot of the activity is going on there or being started there. a state now known worldwide as a hotbed of racial intolerance. be a hotbed of sth a place where a lot of a particular type of activity, especially bad or violent activity, happens
a bed of earth covered with glass and heated by rotting manure to promote the growth of plants a situation that is ideal for rapid development (especially of something bad); "it was a hotbed of vice