Nadezhda (Надежда) is the Russian word for "hope" — the second of three theological virtues (with Vera/faith and Lyubov/love). Saint Nadezhda was martyred with her sisters Vera and Lyubov in 137 CE.
Nadezhda is widely used in Russia. The short form Nadya is also widely used. Nadezhda von Meck was Tchaikovsky's patron and confidante.
Nadezhda 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 Nadezhda reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.