noun ダウンロード 🔗共有 皮脂 A thick oily substance, secreted by the sebaceous glands of the skin, that consists of fat, keratin and cellular debris. Examples : "The teenager's skin was oily because of excess sebum. " 過剰な皮脂のせいで、そのティーンエイジャーの肌は脂っぽかった。 body physiology substance anatomy biology medicine chemistry AIとチャット語彙ゲーム読解練習