Azul is from the Spanish azul (blue) — derived from the Arabic lazaward (lapis lazuli) via Latin. Azul Guaita (born 2001) — Mexican actress. Lake Azul — multiple Latin American geographic features. Azul Almazán — Argentine model. The Azul Brand — major Spanish-American naming/marketing. Café Azul — coffeehouse heritage.
Azul 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 Azul reduce to 6, The Nurturer. This is a traditional interpretive system, not a factual claim about the name.