running
n. uncountable A2 Elementary Oxford US //ˈɹənɪŋ// UK //ɹˈʌnɪŋ// run·ning
n. the activity or sport of moving fast on foot. You do this for exercise, for fun, or to win a race.
n. the action or sport of moving rapidly on foot for exercise or competition. When used as a gerund, it functions as an activity noun.
Running is my favorite way to stay healthy.
She started running every morning to prepare for the local charity race next month.
While some athletes prefer the social aspect of team sports, others find that running offers a unique form of meditative solitude that helps clear the mind.
By surface analysis, run + -ing.
Usage
Typically uncountable when referring to the sport or activity; can be used as a gerund in various sentence positions.