n A contest between people, animals, vehicles, etc. where the goal is to be the first to reach some objective. Several horses run in a horse race, and the first one to reach the finishing post wins
n The bushings of a rolling element bearing which contacts the rolling elements.
v (intransitive) To take part in a race (in the sense of a contest).
v (transitive) To compete against in such a race.
v (intransitive) To move or drive at high speed.
v (intransitive) Of a motor, to run rapidly when not engaged to a transmission.
n A group of sentient beings, particularly people, distinguished by common heritage or characteristics:
n (biology) A population geographically separated from others of its species that develops significantly different characteristics; (non-gloss definition|an informal term for) a subspecies.
n (figuratively) A category or species of something that has emerged or evolved from an older one (with an implied parallel to animal breeding or evolutionary science).