Charles Ellicott 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. — This is evidently formed from the Hebrew hadas, the myrtle: Esther is generally assumed to be a Persian name, meaning a star. Unless we assume that this latter name was given afterwards, and is used here in anticipation, we have here an early case of the common Jewish practice of using two names, a Hebrew and a Gentile one — e.g., Saul, Paul; John, Mark; Joses, Justus, etc.

Uncle. — Abihail .