豆まめ炭たん

noun

(oval) charcoal briquette

A small, often oval-shaped charcoal briquette made from compressed charcoal dust, used for heating or cooking.

• 冬ふゆは豆まめ炭たんをこたつに入いれて使つかいます。

  In winter, we put charcoal briquettes in the kotatsu and use them.