Keziah (קְצִיעָה) is Hebrew for "cassia" — the aromatic spice. In Job 42:14, the second of Job's three daughters born after his restoration. "And in all the land were no women found so fair as the daughters of Job."
Keziah Jones is the Nigerian musician.
Keziah 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 Keziah reduce to 6, The Nurturer. This is a traditional interpretive system, not a factual claim about the name.