Living describes something that is alive: breathing, growing, and able to respond to its surroundings. A living tree pulls water from the soil, reaches toward sunlight, and even heals its own wounds when branches break. Living creatures, from tiny bacteria to enormous whales, all share key abilities: they take in energy, grow, reproduce, and react to the world around them.

Scientists use several tests to determine if something is living. Does it need food or energy? Can it grow and change? Will it eventually reproduce, creating more of its own kind? Does it respond when poked, heated, or moved to a new place? A rock fails all these tests, but a mushroom, a mouse, and a maple tree all pass them.

The word also describes how people conduct their lives. Someone might earn a living by working as a teacher or engineer. A family room might be called a living room because it's where people spend their active, daily time together. When we talk about living conditions, we mean the circumstances in which people actually live day to day.

You might hear someone described as a living legend, meaning they’re still alive and already famous for their achievements. The phrase living proof means someone or something that demonstrates the truth of an idea just by existing.