[mar.a.thon] n, often attrib [Marathon, Greece, site of a victory of Greeks over Persians in 490 b.c., the news of which was carried to Athens by a long-distance runner] (1896) 1: a long-distance race: a: a footrace run on an open course usu. of 26 miles 385 yards (42.2 kilometers) b: a race other than a footrace marked esp. by great length
2. a: an endurance contest "a dance ~" b: something (as an event, activity, or session) characterized by great length or concentrated effort