Refers to a stone used for sharpening blades. Most commonly encountered in the compound 砥石 (といし).
See also: 砥石 (といし)
Sharpen the kitchen knife on a whetstone.
medium-grade millstone
medium-grade whetstone; medium sharpening stone
grindstone sludge; sword-sharpening residue
rough grindstone; coarse whetstone
Standard kanji spelling for whetstone/grindstone; often appears in compounds like 砥石 (といし).
The kanji 砥 is composed of 石 (stone) and 氐 (a phonetic component), originally referring to a stone for sharpening. The reading と is the native Japanese kun'yomi.