A grinder is a tool or machine that breaks something down into smaller pieces by crushing, grinding, or wearing it away.

In a kitchen, you might use a pepper grinder to crush peppercorns into powder by twisting the top, or a meat grinder to turn chunks of beef into ground meat. Coffee grinders crush roasted beans into grounds for brewing. These tools work by pressing and rubbing the material between hard surfaces until it breaks apart.

Larger grinders appear in workshops and factories. An angle grinder is a powerful handheld tool that spins a rough disc at high speed to cut metal, smooth welds, or sharpen blades. Bench grinders sit on workbenches and sharpen tools like chisels and lawn mower blades. The grinding action wears away tiny bits of material, similar to how sandpaper smooths wood.

The word can also describe a long sandwich on a thick roll, stuffed with meats, cheese, and vegetables. Different regions call this same sandwich a sub, hoagie, or hero.

When someone calls themselves a grinder, they mean they succeed through persistent hard work rather than natural talent alone, grinding away at challenges until they overcome them.