热火 rèhuorèhuǒ enthusiastic Origin Definitions Defs Strokes Stroke Words Sentences Sents 热火朝天 rèhuǒcháotiān bustling with activity (idiom) in full swing; buzzing with energy and enthusiasm. Describes a scene that is bustling, animated, or surging with activity.炽热火山云 chìrèhuǒshānyún nuée ardente A fast-moving cloud of hot gas and volcanic ash; a pyroclastic flow