A forerunner is something or someone that comes before and signals what's coming next. When you see dark clouds gathering on the horizon, they're forerunners of a storm. When your stomach rumbles during math class, it's a forerunner of lunchtime hunger.

The word often describes people who pioneer new ideas or methods that others later adopt. The Wright brothers were forerunners of modern aviation: their first shaky flights at Kitty Hawk paved the way for today's jumbo jets. Ancient Greek philosophers were forerunners of modern science, asking questions about nature that scientists still explore today. A forerunner doesn't just predict what's coming; it helps make it possible.

You'll also see forerunner used in contexts like “the abacus was a forerunner of the calculator” or “your rough draft is a forerunner of your final essay.” In each case, the forerunner comes first and points toward something more developed later.