The bottom part of a circular stone hand mill for grinding grain, used as stone material in the garden. It is sometimes used as a path junction stone, or as a water-crossing stone. It is also reworked and used as a water basin. Another name for it is usuishi.
Japanese Garden Dictionary: A Glossary for Japanese Gardens and Their History
(C) 2010 by Ono Kenkichi and Walter Edwards. All rights reserved.