Rhea (Ῥέα) is the Titaness mother of the Olympians — Zeus, Hera, Poseidon, Hades, Demeter, and Hestia. Her name is variously interpreted as "flowing" (from rhein, to flow), "ease," or simply "mother." She is associated with motherhood, fertility, and the flow of generations.
Rhea has been quietly used in English since the 19th century. It is rising in the U.S. Three letters, the mother of all Olympians.
Rhea 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 Rhea reduce to 5, The Seeker. This is a traditional interpretive system, not a factual claim about the name.