Thorhild is from the Old Norse Þórhildr — Thor (the thunder god) + hildr (battle). Þórhildr Jǫrundardóttir (c. 1000 CE, nearly 500 years before Columbus). After her conversion to Christianity (c.
Thorhild is a compound name. Its parts are Þórr + hild — each an attested element with a recorded meaning of its own.
Thorhild 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 Thorhild reduce to 4, The Builder. This is a traditional interpretive system, not a factual claim about the name.