Trinity comes from the Latin trinitas, meaning "three" or "triad" — referring to the Christian concept of God as Father, Son, and Holy Spirit. The name carries direct theological weight.
It peaked at #36 in 2007 and has been declining gradually. Today it sits in the U.S.
Trinity 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 Trinity reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.