Albert Barnes Commentary Esther 2:7

"And he brought up Hadassah, that is, Esther, his uncle`s daughter: for she had neither father nor mother, and the maiden was fair and beautiful; and when her father and mother were dead, Mordecai took her for his own daughter." — Esther 2:7 (ASV)

Hadassah, הדסה hădassâh from הדס hădas (“myrtle”) would seem to have been the Hebrew, and Esther the Persian, name of the young woman. Esther is thought to be connected through the Zend with ἀστήρ astēr — “star.” But there is not at present any positive evidence of the existence in Old Persian of a kindred word.