hotbed
n
1 bed of earth heated by rotting manure to help plants to grow (用糞肥發酵產生熱量的)溫床.
2 (fig 比喻) ~ of sth place where sth evil or undesirable is able to develop easily and freely (有利於壞事物滋生發展的)溫床
a hotbed of vice, crime, intrigue, etc 罪惡、 犯罪、 陰謀活動等的溫床.