Sigyn was the Norse goddess and wife of Loki — who, when Loki was bound in a cave with a venomous serpent dripping poison on his face, held a bowl over him to catch the venom, emptying it only when full, for all eternity.
Featured in the Poetic Edda and Prose Edda.
Sigyn 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 Sigyn reduce to 2, The Peacemaker. This is a traditional interpretive system, not a factual claim about the name.