1. A flat, circular stone wheel used for sharpening tools or grinding grain.
2. A hard, tedious task or burden that wears one down over time.
Usage: figurative

Examples

• The blacksmith used grindstones to sharpen his tools every morning.
• Medieval mills relied on large grindstones to crush wheat into flour.
• Daily paperwork became a grindstone that exhausted the office staff.
• He kept his knives sharp by running them across the grindstones in his workshop.
• The constant demands of the job felt like a grindstone wearing away at her patience.
• Ancient grindstones have been discovered in archaeological sites across the region.