Pinch-runner is a term used in baseball referring to a substitute player who enters the game to run on the bases for a slow player. There are several synonyms for the term pinch-runner. Some of the other common words used are speedster, sprinter, and base stealer, all of which signify the same thing, a fast player with the ability to run quickly from base to base. Other options include fleet-footed player, quick runner, designated base runner, and substitute runner. These synonyms may be used interchangeably, depending on the context of the situation, to refer to a player who is sent in to take over the base running duties for a team.