And he had brought up Hadassah, that is Esther.
וַיְהִי אֹמֵן אֶת הֲדַסָּה הִיא אֶסְתֵּראסתר ב:ז
va-y'-hee o-mayn et ha-da-sa hee es-tayr
Esther is the name that comes to mind as the Jewish heroine of the Purim story, however, in the Megillah, we find that her given name is actually Hadassah.
Why was Esther's name changed, and why has the second name gone down in fame throughout history? If we look at the meaning of the word Esther, we can see why. Esther comes from the Hebrew root se-ter, סתר which means secret.
The miracle of Purim was intertwined with the hidden hand of God 'pulling the strings' throughout the story. Esther embodied the idea of hidden and revealed, how that which is evident to the naked eye does not always represent the full story. The Master of the World is the hidden force behind every salvation, and Esther merited the role in history to orchestrate that salvation.