Where does “zlgwn'” come from?
zlgwn' (Pahlavi) comes from Proto-Iranian jr̥Hanyam, from Proto-Indo-Iranian ȷ́ʰr̥Hanyam, from Proto-Indo-European ǵʰl̥h₃enyom, from Proto-Indo-European ǵʰelh₃- — to flourish; green, yellow.
Ancestry of “zlgwn'”, step by step