Zend-Avesta

The Avesta is the primary collection of sacred texts of Zoroastrianism, composed in the Avestan language. The texts originate over a period spanning most of the 1st millennium BC, and notably include the Old Avestan Gathas, 17 hymns ascribed to Zoroaster himself. The etymology of the term Avesta itself is uncertain, but a derivation from middle Persian , "praise", is a frequently noted possibility.
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Noun
1. a collection of Zoroastrian texts gathered during the 4th or 6th centuries
(synonym) Avesta
(hypernym) sacred text, sacred writing, religious writing, religious text

(n.)
The sacred writings of the ancient Persian religion, attributed to Zoroaster, but chiefly of a later date.
  

[Persian] The sacred writings of the Zoroastrian religion of ancient Persia. 

Zend-Avesta (Pahlavi) [from Old Persian zend commentary, interpretation + aba-ta the law] The writings of the religion of the Parsis, still used by them as the basis of their faith. The Parsis themselves call this collection of documents the Avesta; Zend was principally used by the Parsis to denote the Pahlavi translations and commentaries on the Avesta.