noun
Refers to the burnt remains after something has burned, such as charcoal, wood, or paper. Often used for the glowing remnants of a fire.
キャンプファイヤーの燃えかすを片付ける。
Clean up the cinders from the campfire.
ストーブの燃えかすがまだ赤く光っている。
The embers in the stove are still glowing red.
Compound of 燃え (もえ, the continuative form of 燃える 'to burn') and かす (滓, 'dregs, lees, scum'). The spelling 燃えかす is a common mixed kanji-kana form.