First means coming before all others in time, order, or importance. When you're first in line, nobody stands ahead of you. The first person to finish a race crosses the finish line before everyone else. Your first day of school happens before all the other days that year.

Being first in time creates a special quality: the first person to climb Mount Everest, Edmund Hillary, achieved something nobody had done before. The Wright brothers made the first powered airplane flight. These firsts matter because they open up possibilities for everyone who comes after.

First can also mean most important or primary. Your first priority is the thing that matters most. A doctor's first concern is keeping patients safe. When someone says “safety first,” they mean safety matters more than anything else in that moment.

The word appears everywhere in daily life: first place, first prize, first impression, first aid, first base. There's even first class, the most expensive section of an airplane. Notice how being first can suggest something positive: being earliest, being best, or being most essential. When you do something for the first time, you're experiencing it fresh, which makes it memorable even if you're not literally the first person ever to do it.