marathoner
ma·rat·ho·ner
noun
1.
someone who participates in long-distance races (especially in marathons)
Origin
From marathon + -er.
Related words
Broader terms
WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). WordNet 2.1 Copyright Princeton University. All rights reserved. Wiktionary content is available under the Creative Commons Attribution-ShareAlike Licence.