Mara (מָרָא) is the Hebrew word for "bitter." In the Book of Ruth, Naomi changes her own name to Mara after the deaths of her husband and sons: "Call me not Naomi, call me Mara, for the Almighty hath dealt very bitterly with me" (Ruth 1:20).
Mara is widely used in modern Israel and globally — distinct from Italian Mara (short for Maria).
Mara 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 Mara reduce to 6, The Nurturer. This is a traditional interpretive system, not a factual claim about the name.