Mathilda is the Germanic original spelling of Matilda — from maht (might, strength) + hild (battle). A modern revival in the vintage-Germanic aesthetic. Saint Mathilda of Ringelheim (c. 894-968) — Queen consort of East Francia. "Waltzing Matilda" — Australia's most-iconic song (1895).
Mathilda is a compound name. Its parts are hild — each an attested element with a recorded meaning of its own.
Mathilda 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 Mathilda reduce to 5, The Seeker. This is a traditional interpretive system, not a factual claim about the name.