ichidan verb, intransitive verb
become sooty; get stained with soot
Describes surfaces or objects that have become darkened or discolored by soot or smoke over time.
長年使った天井がすすけて黒くなった。
The ceiling, used for many years, became sooty and turned black.
暖炉の上の壁がすすけている。
The wall above the fireplace is stained with soot.