A flood occurs when water overflows onto land that is normally dry. Heavy rainstorms can cause rivers to rise above their banks and spread across fields, roads, and even into homes. Melting snow in spring sometimes creates floods when too much water flows into rivers at once. Coastal areas face floods during hurricanes when powerful winds push ocean water onto the shore.

Floods can be destructive, damaging buildings and washing away crops, but they also played an important role in human history. Ancient Egyptians depended on yearly floods from the Nile River, which deposited rich soil across their farmland, making it possible to grow abundant crops in the desert. Many early civilizations developed near rivers partly because seasonal flooding made the land fertile.

The word also means an overwhelming amount of something. After winning the championship, the team received a flood of congratulations. A popular new video game might flood stores with customers. When your inbox fills with dozens of emails at once, you might say you've been flooded with messages. This usage captures that same sense of being overwhelmed, like water spilling over its usual boundaries.