From Proto-Tocharian*pä́rwë, from Proto-Indo-European*pṛh₂wo-(“anterior”), compare *per- (cognate to Sanskrit पूर्व(pūrva), Avestan 𐬞𐬀𐬎𐬭𐬬𐬀(paurva), Old Church Slavonic пръвъ(prŭvŭ), Albanian parë); the final -t was added as in other ordinal numbers, and a similar process is visible in English first, Old English fyrst, fyrest, forewost, forewest, equivalent to English fore + -est). Compare Tocharian B parwe.