Selah is a character from Song of the Ovulum. She is the teenaged daughter of Methuselah and sister of Joran.
"Selah" is a notation commonly used in the Bible, especially Psalms. It means something like "stop and listen" and was probably meant to either indicate a pause in a song or stess the importance of the previous words.
It is also the last few letters of Methuselah, her father.