The act of sharpening or grinding a blade or tool (or the result); sharpening done with a whetstone, grinder, etc.
包丁の研ぎが悪くて野菜がきれいに切れない。
The knife is poorly sharpened, so it doesn't cut vegetables cleanly.
古いナイフを研ぎに出したら、切れ味が戻った。
I had an old knife sharpened and its cutting ability returned.
職人は研ぎ石で包丁を研ぐのが得意だ。
The craftsman is skilled at sharpening knives with a whetstone.