Where does “raz” come from?

raz (Norman) comes from Old Norse rás, from Proto-Germanic rēsō, from Proto-Indo-European reh₁s- — to flow, rush.

raz (Norman): race

Definitions

Step	Language	Word	Meaning
1	Old Norse	rás	race, running; course, channel; company, host
2	Proto-Germanic	rēsō	a running; a course; a rush
3	Proto-Indo-European	reh₁s-	to flow, rush

raz — Etymology, Origin & Word History | Etymology Explorer