Dinah (דִּינָה) comes from the Hebrew din, meaning "judgment" — giving "judged" or "vindicated." In Genesis, Dinah is the only named daughter of Jacob and Leah.
Dinah was popular in the 19th century, peaking at #97 in 1880. After a long quiet it is returning as part of the broader return of biblical names. Lewis Carroll's Alice has a cat named Dinah.
Dinah 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 Dinah reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.