The Japanese name for the Celadon Urn is せいじのつぼ (Seiji no Tsubo). Seiji means celadon or celadon porcelain. It started in China and spread to other countries in the area. It usually refers to pottery glazed with a special greenish color known as celadon which looks similar to the color of jade.
It has the same Japanese name as the Celadon Pot from later games.