hypocaust
/ˈhaɪpəʊkɔːst/noun
- a hollow space under the floor of an ancient Roman building, into which hot air was sent for heating a room or bath（古罗马）地底供暖火坑。
词源
from Latin hypocaustum, from Greek hupokauston 'place heated from below', from hupo 'under' + kau- （base of kaiein 'to burn'）.