Nimue (also Niniane, Viviane, Vivien) is of obscure Celtic origin. The chief Lady of the Lake in the Arthurian cycle — the enchantress who gave King Arthur the sword Excalibur from her lake and received it back when Sir Bedivere threw it to her as Arthur lay dying. She seduced and entrapped Merlin in an enchanted oak tree (or stone), ending his role in Arthur's story. She fostered Sir Lancelot after his father's death, raising him in her underwater realm — hence "Lancelot du Lac." Among the most enduring Celtic-Arthurian figures in Western literature.
Featured throughout Malory's Le Morte d'Arthur and Tennyson's Idylls of the King.
Nimue 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 Nimue reduce to 8, The Visionary. This is a traditional interpretive system, not a factual claim about the name.