A person or thing that completes something, or in racing, someone who crosses the finish line.
From finish + -er (agent suffix indicating one who does an action). This compound became standardized in English in the 1800s, particularly in sports contexts.
In horse racing and cycling, a 'finisher' has a specific meaning—it's not just someone who finishes, but someone who performs well in the final stages—which is why sprinters and climbers can be very different types of finishers.
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