noun ダウンロード 🔗共有 ウキクサ Any of several reduced floating aquatic plants in the subfamily Lemnoideae of the family Araceae. Examples : "The pond was covered in a thick green layer of duckweed. " 池は、厚い緑色のウキクサの層で覆われていた。 plant biology ecology environment nature AIとチャット語彙ゲーム読解練習