racer
A person or vehicle that competes in a race.
A racer is someone who competes in races, trying to reach the finish line before anyone else. Racers might sprint on a track, pedal bicycles through mountain trails, drive cars around oval speedways, or pilot boats across choppy water. What makes someone a racer is the commitment to competing against others or against the clock, combined with the speed and skill to do it well.
Professional racers dedicate years to perfecting their skills and reflexes. A Formula 1 racer must make split-second decisions at 200 miles per hour. A marathon racer trains their body to maintain a strong pace for over 26 miles. But you don't need to be a professional to be a racer: kids who join their school's cross-country team or compete in soapbox derbies are racers too.
The word can also describe the vehicle itself. A sleek bicycle built for speed might be called a racer, and toy cars designed to zoom down orange plastic tracks are often called racers. Whether describing the person or the machine, the word captures that same spirit: built for speed, designed to compete, always pushing toward the finish line.