Die has two main meanings:

1. To stop living. All living things eventually die: plants wither, animals die, and humans reach the end of their lives. In stories, characters might die heroically saving others, or villains might meet their end after their evil plans fail. Scientists study why and how organisms die to better understand life itself. People also use “die” less literally: a conversation might die down when everyone stops talking, or a fire dies out when it runs out of fuel. When batteries die, they've simply run out of power.
2. A small cube used in games, with dots (called pips) numbered one through six on its faces. When you roll a die, it tumbles and lands showing one number. Most games use two dice (the plural of die) at once. Board games like Monopoly and Parcheesi rely on dice rolls to determine how far players move. The randomness makes games exciting because no one knows what number will come up.