race (n.1)

"act of running," c. 1300, from Old Norse ras "running, rush (of water)," cognate with Old English ræs "a running, a rush, a leap, jump; a storming, an attack;" or else a survival of the Old English word with spelling influenced by the Old Norse one. The Norse and Old English words are from Proto-Germanic *res- (source also of Middle Dutch rasen "to rave, rage," German rasen, Old English raesettan "to rage" (of fire)), from a variant form of PIE *ers- (1) "be in motion" (see err). Originally a northern word, it became general in English c. 1550. Meaning "act of running" is from early 14c. Meaning "contest of speed" first recorded 1510s.

"people of common descent," a word from the 16th century, from Middle French race, earlier razza "race, breed, lineage, family" (16c.), possibly from Italian razza, of unknown origin (cognate with Spanish and Portuguese raza). Etymologists say no connection with Latin radix "root," though they admit this might have influenced the "tribe, nation" sense.

Original senses in English included "wines with characteristic flavor" (1520), "group of people with common occupation" (c. 1500), and "generation" (1540s). Meaning "tribe, nation, or people regarded as of common stock" is by 1560s. Modern meaning of "one of the great divisions of mankind based on physical peculiarities" is from 1774 (though as OED points out, even among anthropologists there never has been an accepted classification of these).

Just being a Negro doesn't qualify you to understand the race situation any more than being sick makes you an expert on medicine. [Dick Gregory, 1964]

In mid-20c. U.S. music catalogues, "Negro." Klein suggests these derive from Arabic ra's "head, beginning, origin" (compare Hebrew rosh). Old English þeode meant both "race, folk, nation" and "language;" as a verb, geþeodan, it meant "to unite, to join."

c. 1200, rasen "to rush," from a Scandinavian source akin to the source of race (n.1), reinforced by the noun in English and by Old English cognate ræsan "to rush headlong, hasten, enter rashly." Meaning "run swiftly" is from 1757. Meaning "run in competition against" is from 1809. Transitive sense of "cause to run" is from 1860. In reference to an engine, etc., "run with uncontrolled speed," from 1862. Related: Raced; racing.

"strong current of water," c. 1300, originally any forward movement or swift running, but especially of water, from Old Norse ras "a rushing" (see race (n.1)). Via Norman French the word entered French as ras, which might have given English race its specialized meaning of "channel of a stream" (especially an artificial one to a mill), which is recorded in English from 1560s.