Hadassah (הֲדַסָּה) is the original Hebrew name of the biblical Queen Esther — the Persian queen who saved the Jewish people from destruction. In Hebrew tradition, Esther was her name at court; Hadassah was her name at home. The name means "myrtle tree," a plant of Jewish ritual significance.
Hadassah is the name of one of the largest Jewish women's organisations in the world (the Women's Zionist Organization of America). The name is rising in the U.S.
Hadassah does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Hadassah reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.