suffix
Suffix attached to nouns to form words for running events or races, e.g. 100メートル走 (100-meter dash), マラソン走 (marathon run).
彼は100メートル走で優勝した。
He won the 100-meter dash.
駅伝走は長距離のリレー競技だ。
Ekiden running is a long-distance relay race.
競走 is a noun meaning 'race' or 'running competition', while 走 is a suffix used to form compound nouns for specific running events.
走る is the verb 'to run', whereas 走 is a bound suffix used in compound nouns.
The kanji 走 means 'run'. As a suffix, it derives from the on'yomi reading そう and is used in compound nouns for running events.