1. A sacred book of the Guebres or Parsees, ascribed to Zoroaster, and reverenced as a bible or sole rule of faith and practice.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• xend-avesta,
• send-avesta,
• aend-avesta,
• zwnd-avesta,
• zsnd-avesta,
• zdnd-avesta,
• zrnd-avesta,
• z4nd-avesta,
• z3nd-avesta,
• zebd-avesta,
• zemd-avesta,
• zejd-avesta,
• zehd-avesta,
• zens-avesta,
• zenx-avesta,
• zenc-avesta,
• zenf-avesta,
• zenr-avesta,
• zene-avesta,
• zend0avesta

The adjective form of the word "Zend-Avesta" is "Zend-Avestan".

The plural form of "zend-avesta" remains the same and does not change.

The singular form of the word "Zend-Avesta" is "Zend-Avesta". It is a proper noun and does not have a specific singular form.