Adah (עָדָה) is the Hebrew word for "ornament" or "adornment" — from the same root as the modern Israeli name Adi. In Genesis 4:19, Adah was one of the first two named women in the Bible — the wife of Lamech.
Adah was used by Quaker and Mormon families. The famous Adah Isaacs Menken (1835-1868) was an American actress and poet.
Adah 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 Adah reduce to 5, The Seeker. This is a traditional interpretive system, not a factual claim about the name.