1. Sports.
   1. A cross-country footrace of 26 miles, 385 yards (42.195 kilometers).
   2. A long-distance race other than a footrace: a swimming marathon.
2. 1. A contest of endurance: a dance marathon.
   2. An event or activity that requires prolonged effort or endurance.

[After MARATHON (so called because a messenger ran from there to Athens to announce a victory over the Persians in 490).]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.