The name Mirin is a boy's name of Gaelic, Scottish, Irish origin. Mirin and discussed in our forums with posts like "Quick Question Thread?!".
From the experts:
The 6th century Irish saint Mirin emigrated to Scotland and now is the patron saint of both the Glasgow suburb of Paisley and the game of football. Mirren is one modern spelling; the Cornish Merryn, best known as the name of the seacoast town St. Merryn, is also related. The name is usually used for girls.