马兜铃酸 Traditional form: 馬兜鈴酸 Pinyin (reading): mǎdōulíngsuān Definitions: aristolochic acid Characters: 马 - horse; surname 兜 - pouch 铃 - small bell 酸 - tart, sour; spoiled; acid Traditional characters: 馬 - horse; surname 兜 - pouch 鈴 - small bell 酸 - tart, sour; spoiled; acid