[count] 1 a : a person who runs as part of a sport, for exercise, or in a race
▪ a long-distance/cross-country/marathon runner ▪ She's a fast runner.
b : an animal (such as a horse) that runs in a race 2 a : a person who delivers messages, reports, materials, or products either within a business or organization or to outside locations : messenger
b : a person who brings drugs, guns, etc., to a place illegally and secretly
▪ a drug runner 3 baseball : a player who is on base or is trying to reach a base : base runner
▪ The runner slid into third base. 4 : a long, thin piece or part on which something (such as a sled, skate, or drawer) slides 5 : a stem of a plant that grows along the ground and that forms new plants
▪ a plant that spreads by sending out runners 6 a : a long, narrow carpet for a hall or staircase
b : a narrow cloth cover for a table or other piece of furniture