ìm-thòaⁿ窨炭

to put burning charcoal into a jar or porcelain

to put burning charcoal into a jar or porcelain pot and covering it (to extinguish the charcoal flame); loosely structured charcoal (extinguished by putting in a jar or porcelain pot and covering it)

English Wiktionary, “窨炭” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E7%AA%A8%E7%82%AD · confidence: Medium (Wiktionary)