The name Muireann is a girl's name of Irish origin meaning "sea white, sea fair". Muireann and is often added to lists like Names That Mean Fair and discussed in our forums with posts like "Outlandish this-or-that [girls]".
From the experts:
The popular Irish name Muireann comes from a mythical mermaid who was tranformed into a woman by a saint. Pronunciation is like the surname of the actress Helen Mirren, but with the spin of a w sound after the initial M.