source: By Madhurantakam - Own work, CC BY-SA 3.0

the principal church of a diocese, with which the bishop is officially associated: 司教が公式に結びついてる、司教区の最も重要な教会

大聖堂, 司教, 主教座聖堂〘司教, 主教(bishop)の管轄する教区(diocese)にあり法座(cathedra)を備える〙

e.g. in names : St. Paul's Cathedral.: セント・ポール大聖堂

Middle English (as an adjective, the noun being short for cathedral church ‘the church which contains the bishop's throne’): from late Latin cathedralis, from Latin cathedra ‘seat’, from Greek kathedra.