noun
charcoal briquette; coal briquette
A compressed block of charcoal or coal dust used as fuel, especially in traditional heating or cooking.
冬は練炭を使って部屋を暖める。
In winter, we use charcoal briquettes to heat the room.
練炭に火をつけるのに少し時間がかかる。
It takes a little time to light a charcoal briquette.
From 練 (knead, refine) + 炭 (charcoal), referring to charcoal dust that is kneaded with a binder and pressed into shape.