Youngest means being the least old in a group, or having lived or existed for the shortest amount of time. In a family with three children, the youngest is the one born last. In a classroom, the youngest student might be someone who just turned ten while others are already eleven.

Being the youngest often comes with its own experiences. Youngest siblings sometimes feel they have to work harder to keep up with older brothers and sisters, but they also get to learn from watching them. The youngest player on a sports team might have less experience but also bring fresh energy and enthusiasm.

The word can apply to things too, not just people. The youngest tree in a forest is the one that sprouted most recently. The youngest building in town is the one constructed last. Scientists talk about the youngest rocks on Earth, meaning those formed most recently.

You might hear someone called a youngster, which is an informal, friendly way to refer to a young person. And when someone is described as young at heart, it means they have an energetic, curious spirit regardless of their actual age.