hotbeds

Noun

hotbed (plural hotbeds)

1. 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, like a miniature hothouse.
   • Near-synonym: hotbox

   Synonyms:

   hotbox

2. (broadly) An environment that is ideal for the growth or development of something, especially of something undesirable.
   • The problem faced by Government and railway alike is the dreadful legacy of the 'stay home' policy which has left millions of people fearing that trains are a hotbed of infection to be avoided like the... well, do I have to say it?!2020 August 12, Nigel Harris, “Comment: Rail at the brink? Not yet...”, in Rail, page 3

   Synonyms:

   seedbed

3. An iron platform in a rolling mill, on which hot bars, rails, etc., are laid to cool.