Hail has two completely different meanings:

1. Frozen rain that falls as small balls or lumps of ice, usually during thunderstorms. When warm air rushes upward in a storm cloud, it can freeze raindrops and toss them around until they grow into ice pellets. These fall as hail, sometimes as small as peas, sometimes as large as golf balls or even baseballs. A hailstorm can dent cars, shatter windows, and flatten crops in minutes. Farmers worry about hail because it can destroy an entire harvest.
2. To greet someone enthusiastically or to call out to get their attention. You might hail a taxi by waving your arm to flag it down, or hail a friend across a crowded playground. In older times, people would hail a king or queen as they passed, celebrating their presence. The phrase “Hail to the Chief” honors the president. When you hail from a place, it means you come from there originally: “She hails from Boston” means Boston is her hometown.