英语词源字典 - 在线词源网站

in medias res [in medias res 词源字典]: Latin, literally "in the midst of things" (see medium).[in medias res etymology, in medias res origin, 英语词源]
mediastinum: "A membranous partition between two body cavities or two parts of an organ, especially that between the lungs", Late Middle English: neuter of medieval Latin mediastinus 'medial', based on Latin medius 'middle'.