Where does “rəvan” come from?

rəvan (Azerbaijani) comes from Persian روان, from French Rouen, from Old French Roem, from Latin Rotomagus, from Gaulish Ratumacos, from Gaulish magos, from Proto-Celtic magos, from Proto-Indo-European meǵh₂- — big, great; great; big, stour, great.

rəvan (Azerbaijani): smooth, even

Definitions

smooth, even

Ancestry of “rəvan”, step by step

Step	Language	Word	Meaning
1	Persian	روان	fluid; flowing; fluent
2	French	Rouen	—
3	Old French	Roem	—
4	Latin	Rotomagus	The chief city of the Veliocasses in Gallia Lugdunensis, now Rouen
5	Gaulish	Ratumacos	—
6	Gaulish	magos	field
7	Proto-Celtic	magos	plain, field
8	Proto-Indo-European	meǵh₂-	big, great; great; big, stour, great

Every word from Proto-Indo-European meǵh₂- →Every word from Proto-Celtic magos →Every word from Gaulish magos →