Birth is the moment when a baby comes out of its mother's body and begins life in the world. For nine months before birth, a baby grows inside its mother's womb, a special protective space in her body. At birth, the baby emerges, takes its first breath, and begins life as a separate person.

Every person you've ever met, every historical figure you've read about, every character in every story: they all entered the world through birth. Your own birthday marks the anniversary of your birth, the day you arrived and your life began.

The word also describes the beginning or origin of something new. The birth of a new invention, like the birth of the airplane or the birth of the internet, marks when something important first appeared. A new idea can give birth to a movement or a discovery. When America declared independence, it marked the birth of a nation.

You might hear phrases like birth order (whether you're the oldest, middle, or youngest child) or birthplace (the town or country where you were born). The word birthday combines birth with day: the specific date when you were born, which you celebrate each year.