1 chiefly Scotland : the act of running
2a : a strong or rapid current of water flowing through a narrow channel
b : a watercourse used industrially
c : the current flowing in such a course
3a : a set course or duration of time
b : the course of life
4a : a contest of speed
b races plural : a meeting in which several races (as for horses) are run
c : a contest or rivalry involving progress toward a goal
//pennant race
5 : a track or channel in which something rolls or slides
specifically : a groove (as for the balls) in a bearing
— see roller bearing illustration
https://www.merriam-webster.com/dictionary/race