noun
medium-grade whetstone; medium sharpening stone
A sharpening stone of medium coarseness, used between rough and fine stones in a sharpening progression.
包丁を研ぐときは、まず荒砥、次に中砥、最後に仕上げ砥を使います。
When sharpening a kitchen knife, first use a coarse stone, then a medium stone, and finally a finishing stone.