Merida is from the Spanish city Mérida in Extremadura — itself from Latin Augusta Emerita, founded 25 BCE for retired Roman soldiers (emeriti, "those who have earned"). Princess Merida — the protagonist of Pixar's Brave (2012) — is Pixar's first lead female protagonist and the first Disney princess who does not have a romantic interest; voiced by Kelly Macdonald. Brave won the 2013 Academy Award for Best Animated Feature and the Golden Globe; set in the Scottish Highlands, Merida is also Disney's first redheaded princess and the first to be inspired by Scottish folklore and the legends of the Picts. The name has charted in US records since 2012.
Subject of countless 2010s animation studies.
Merida 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 Merida reduce to 5, The Seeker. This is a traditional interpretive system, not a factual claim about the name.