The Welsh goddess of the silver wheel — the moon, the stars, and the spinning of fate — whose celestial castle Caer Arianrhod is identified with the constellation Corona Borealis.
Featured in the Mabinogion.
Arianrhod 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 Arianrhod reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.