Mairi is the Scottish Gaelic form of Mary.
Mairi Mhòr nan Òran (Mary MacPherson, 1821-1898) was the great Scottish Gaelic poet known as "Big Mary of the Songs."
Mairi 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 Mairi reduce to 5, The Seeker. This is a traditional interpretive system, not a factual claim about the name.