marathon
n. countablen. a long race where people run about 42 kilometers. You can also use this word to describe any activity that takes a very long time and requires a lot of energy.
n. a long-distance running race with an official distance of 42.195 kilometres. Figuratively, any activity or event that is exceptionally long and requires great endurance.
She is training hard for her first marathon.
The negotiation turned into a twelve-hour marathon that left both sides completely exhausted by midnight.
Completing a marathon requires not only physical stamina but also the psychological fortitude to maintain a steady pace when the body begins to fail around the thirty-kilometre mark.
From Ancient Greek Μαραθών (Marathṓn). Doublet of marathon.
Often used as a noun adjunct to modify other nouns, such as 'marathon session' or 'marathon meeting'.