Hollow-ground is a term used mostly in the context of knives and blades. It refers to the concave shape of the blade which is made by grinding away the metal along the length of the blade. This shape enables the blade to be sharper and have better edge retention. The word hollow-ground can be replaced with other synonyms such as concave-ground, tapered, cut-out, and sunken-edge. These words are used to describe the same shape and design of the blade that enables it to be more efficient and effective in its cutting abilities. Whatever the word chosen, it's clear that the hollow-ground design is a fundamental feature of many knives and blades.