Uned is a battlestar in the Colonial Fleet.
She is presumed to be destroyed by early Cylon attacks during the Fall of the Twelve Colonies.
Galactica communications officer Anastasia "Dee" Dualla informed Lt. Felix Gaeta that "One report said an entire Battlestar lost power just before it came in contact with the enemy. They said it was like someone just turned off a switch." As this exchange largely mirrors the message printed out it can be assumed that the battlestar in question was the Uned. http://media.battlestarwiki.org/images/e/e4/Battlestar_Uned_message.gif
There is nothing in any mythology with the name "Uned", so it is highly probable that the name is strictly a creation from the show's Prop Department.