Mairead means "pearl" — it is the Irish and Scottish Gaelic form of Margaret, which traces back through Latin Margarita to the Greek word margarites, meaning a pearl.
Maisey
Maisey is a pet form of Margaret or Mary, carrying the traditional meaning of "pearl" (from Margaret) or "beloved" and "wished-for child" (from Mary). It has a soft, approachable feel that softens the more formal roots of its parent names.