Inherited from Old Italian riga, from Lombardic rīga (“line, row”), from Proto-Germanic *rīgǭ, from Proto-Indo-European *h₁reyk- (-kh-) (“to scratch, cut”). Akin to Old High German rīga (“line”) (German Reihe (“row, series”)), Old Norse rēga (“string”) (Norwegian reig (“row, line”), Middle Dutch rīe (“line, row”), Old English rǣw (“line, row”).