Source : Webster's Revised Unabridged Dictionary (1913)

Zend \Zend\, n. [See {Zend-Avesta}.]
   Properly, the translation and exposition in the Huzv[^a]resh,
   or literary Pehlevi, language, of the Avesta, the Zoroastrian
   sacred writings; as commonly used, the language (an ancient
   Persian dialect) in which the Avesta is written.

Avestan \A*ves"tan\, a.
   Of or pertaining to the Avesta or the language of the Avesta.
   -- n. The language of the Avesta; -- less properly called
   {Zend}.

Source : WordNet®

Zend
     n : an ancient Iranian language [syn: {Avestan}]