Jecoliah (יְכָלְיָה) means "YHWH is able" or "YHWH has prevailed" in Hebrew. In 2 Kings 15:2, Jecoliah was the mother of King Uzziah (Azariah) of Judah — one of Judah's most prosperous rulers, whose 52-year reign coincided with the prophet Isaiah's early years.
Rare but iconic in biblical scholarship.
Jecoliah 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 Jecoliah reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.