To amass means to gather together a large amount of something over time. When a collector amasses baseball cards, they build an impressive collection through years of trading, purchasing, and searching. A squirrel amasses acorns for winter, storing hundreds of them in various hiding spots.

The word suggests both quantity and effort. You might earn five dollars, but you amass savings by consistently adding money to your account over months or years. A library amasses books through decades of careful acquisition. A general might amass troops before a battle, gathering forces from different locations into one powerful army.

Notice the difference between simply having something and amassing it: amassing emphasizes the active process of accumulation. Think of how a snowball becomes larger as it rolls downhill, continuously gathering more snow. That's the feeling of amassing, whether you're amassing knowledge by reading hundreds of books, amassing evidence to support a theory, or amassing supporters for a cause you believe in. The power of amassing lies in both what you end up with and the steady determination it takes to build something substantial.