1.  avestan(n = noun.communication) zend - an ancient Iranian language;
is a kind of iranian, iranian language
Derived form adjective avestan₁

2.  avestan(n = noun.communication) - the script in which the ancient Persian language of the Avesta is written;
is a kind of script
Derived form adjective avestan₁

   avestan(a = adj.pert) - of or pertaining to the Avesta (sacred text of Zoroastrianism);
Derived forms noun avesta₁, noun avestan₂, noun avestan₁

   Of or pertaining to the Avesta or the language of the Avesta. [Webster 1913 Suppl.]

avestan, adj. & n.
--adj. of or relating to the Avesta.
--n. the ancient Iranian language of the Avesta.