Glenda is from the Welsh glân (clean, holy) + da (good) — "holy good." A top-150 US baby name from 1937 to 1969. CBE (1978). Glenda Bailey — British editor; Harper's Bazaar 2001-2020. Glenda the Good Witch is also the central character of Stephen Schwartz's Wicked (Broadway 2003, film 2024).
Glenda 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 Glenda reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.