Montserrat is from the Catalan Mont serrat (jagged mountain) — referring to the iconic Catalan mountain near Barcelona. Montserrat Roig (1946-1991) — Catalan novelist. Montserrat, Caribbean — British Overseas Territory.
Montserrat 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 Montserrat reduce to 8, The Visionary. This is a traditional interpretive system, not a factual claim about the name.