A person who or animal which goes the distance; (originally Horse Racing) a horse able to hold out until the end of a race; (later Baseball) a pitcher who pitches for an entire game; compare to go the route.
Origin
1920s; earliest use found in The Washington Post.
Definition of route-goer in US English:
route-goer
noun
US Sport
A person who or animal which goes the distance; (originally Horse Racing) a horse able to hold out until the end of a race; (later Baseball) a pitcher who pitches for an entire game; compare to go the route.