Mathilde is the French and German form of Matilda — combining the Germanic maht (might) and hild (battle), meaning "mighty in battle." Princess Mathilde Bonaparte (1820-1904) was a famous Parisian salonnière.
Mathilde is widely used in France.
Mathilde is a compound name. Its parts are hild — each an attested element with a recorded meaning of its own.
Mathilde 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 Mathilde reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.