ultrarunningEnglishOxford New American Dictionaryultrarunning /ˈəltrəˌrəniNG, ˈəltrəˌrənɪŋ / ▸ noun the sport or activity of competing in ultramarathons: in the world of ultrarunning, women outperforming men isn't surprising. – DERIVATIVES ultrarunner /ˈəltrəˌrənər/ noun