1. the period of time before written records were kept
2. the early background or origins of something before it became well-known or important

Examples

• Archaeologists study tools and artifacts from prehistory.
• Cave paintings provide glimpses into human life during prehistory.
• The invention of writing marked the end of prehistory.
• Dinosaurs lived in prehistory, millions of years before humans.
• The prehistory of the internet began with early computer networks.
• She researched the prehistory of the civil rights movement.
• The company’s prehistory as a small startup is fascinating.