Penarddun is the Welsh mythological queen — daughter of Beli Mawr, wife of Llŷr, mother of Brân the Blessed, Branwen, and Manawydan. She is one of the most important matriarchs of the Mabinogion.
Featured in the Second Branch of the Mabinogion.
Penarddun 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 Penarddun reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.