race (2)
"people of common descent," c.1500, from M.Fr. razza "race, breed, lineage," possibly from It. razza, of unknown origin (cf. Sp., Port. raza). Original senses in Eng. included "wines with characteristic flavor" (1520), "group of people with common occupation" (c.1500), and "generation" (c.1560). Meaning "tribe, nation, or people regarded as of common stock" is from c.1600. Modern meaning of "one of the great divisions of mankind based on physical peculiarities" is from 1774 (though even among anthropologists there never has been an accepted classification of these). Klein suggests these derive from Arabic ra's "head, beginning, origin" (cf. Heb. rosh). O.E. þeode meant both "race" and "language;" as a verb, geþeodan, it meant "to unite, to join." Racial is first attested 1862. Race-riot attested from 1890.
http://www.etymonline.com/index.php?term=raceThere's also a discussion thread in the sci.lang newsgroup at
http://groups.google.com/group/sci.lang/browse_thread/thread/65ec10ca223e0dde/d2428050e3fa6d4e?lnk=st&q=German+lexicographers+seem+to+have+agreed+that+%22race%22%2F%22Rasse%22+comes+from+Arabic+%2Fra's%2F+'head'%2C&rnum=1