whetstone
/ˈwɛtˌstoʊn/
noun
- A stone used for sharpening blades or tools.
- After years of use, the whetstone had a groove worn into its surface.
- He used a whetstone to put a fine edge on his kitchen knives.
- The carpenter kept a whetstone in his toolbox for his chisels.
- Something that sharpens or hones a skill, ability, or quality.
- The rigorous training program served as a whetstone for the young athletes.
- Criticism, when constructive, can be a whetstone for improving your work.
- Difficult challenges can be a whetstone for a person's character.
Synonyms