cathedral: [13] Cathedral is a shortening of cathedral church, which was originally the ‘church housing the bishop’s throne’. For ultimately cathedral comes from Greek kathédrā (source also of English chair), a compound noun meaning ‘seat’, formed from katá- ‘down’ and *hed- ‘sit’. The adjectival form was created in late Latin as cathedrālis, and reached English via Old French. The notion of the bishop’s authority residing in his throne recurs in see, which comes from Latin sēdem ‘seat’, a relative of English sit. => chair[cathedral etymology, cathedral origin, 英语词源]