sprinter
Word family
Synonym discussion
Sense: noun/1
Runner is the broadest term for anyone who runs, whether competitively or for exercise. A sprinter is a specific type of runner who focuses on short distances (up to 400 metres) where maximum speed matters most — this is the key difference. Racer overlaps with both but shifts the emphasis to the competitive aspect; a racer can compete in foot races, car races, or bike races, while a sprinter is limited to sprinting. For example, a person who jogs every morning is a runner but not a sprinter or a racer. Usain Bolt is both a runner and a sprinter, and also a racer when he competes. A child in a school sack race is a racer but definitely not a sprinter.
Etymology
Sprinter comes from the verb 'sprint', which appeared in English around the 1500s meaning 'to spring or leap forward'. It probably comes from an Old Norse word 'sprinta' (to jump, to split). By the late 1800s, 'sprint' was used for a short burst of fast running in athletics, and 'sprinter' for the person doing it.