Queen Brunhilda of Austrasia (c. 543-613) was the Visigothic-Frankish queen — wife of King Sigebert I, regent for her son and grandsons through five decades of brutal power politics.
Brunhilda is a compound name. Its parts are hild — each an attested element with a recorded meaning of its own.
Brunhilda 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 Brunhilda reduce to 8, The Visionary. This is a traditional interpretive system, not a factual claim about the name.