Wilder is from the Old Germanic wild (untamed, wild) — a modern American word-name; also a surname carried by famous literary figures. Wilder Vaughan — celebrity baby name. The name reflects the broader American word-name trend.
Wilder 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 Wilder reduce to 8, The Visionary. This is a traditional interpretive system, not a factual claim about the name.