"in the matter of, in the (legal) case of," c. 1600, probably from Duns Scotus; Latin, from re, ablative of res "property, goods; matter, thing, affair," from Proto-Italic *re-, of uncertain origin. According to de Vaan from PIE *Hreh-i- "wealth, goods" (cognates Sanskrit rayi- "property, goods," Avestan raii-i- "wealth").
