Younger Avestan: The Language of the Bulk of the Avesta

Younger Avestan is the later and more extensive of Avestan's two historical layers, in which the great majority of the Avesta beyond the Gathas was composed, including the Yasna liturgy's remaining sections, the Yashts, hymns addressed to individual Zoroastrian divine and semi-divine figures, and the Vendidad, a text of priestly and purity law, and it shows grammatical simplification and vocabulary development relative to the more archaic Old Avestan of the Gathas, reflecting a later stage of the same Indo-Iranian linguistic tradition.

Younger Avestan belongs to the Indo-Iranian branch of the Indo-European family, and its composition likely spanned several centuries and possibly different regions of the ancient Iranian-speaking world, producing some internal grammatical variation scholars have used to help reconstruct the Avesta's compositional history and geography even though the text's precise chronology remains debated. Like Old Avestan, Younger Avestan ceased to function as anyone's everyday spoken language in antiquity, surviving purely as a fixed liturgical register transmitted through specialized priestly memorization for many centuries before eventual written codification.