The Nuttall Encyclopedia
Name applied, mistakenly it would seem, by the Europeans to the ancient Iranian language of Persia, or the language in which the Zend-Avesta is written, closely related to the Sanskrit of the Vedas it appears.
Wood, James, ed. Entry for 'Zend'. The Nuttall Encyclopedia. https://www.studylight.org/encyclopedias/eng/nut/z/zend.html. Frederick Warne & Co Ltd. London. 1900.