Cliodhna (also Clíona) is the Irish goddess of love, beauty, and the Otherworld — queen of the banshees of southern Ireland. Three brightly-colored magical birds were her companions, and Cliodhna's Wave (Tonn Chlíodhna) was one of the three great waves of Ireland.
Used widely in modern Ireland.
Cliodhna 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 Cliodhna reduce to 3, The Communicator. This is a traditional interpretive system, not a factual claim about the name.