1. hot bed - Noun
2. hot bed - Verb
A mass of organic matter decomposing and giving off heat from microbial metabolic action.
A garden bed using such a heat-generating mass; a hotbox.
A central point of activity, relating to a specific task.
A bed shared by workers, sailors, or soldiers operating in shifts or watches (named for the idea that it is still warm when the next occupant gets into it).
Reusing sleeping quarters in shifts.
The crew of the submarine quickly got used to hot bedding.
To farm using hotbeds for season extension.
Source: en.wiktionary.org