In more recent times, the word has migrated to the rest of Munster and particularly to Limerick. In Limerick it underwent a conversion of sorts and now is used to mean a boy or a girl.
It can be 1. a term of affection for a friend
2. A word for a particularly good looking boy/girl
3. A word for someone who is a bit of a legend (cool person)
2. Didya see your man in the park? He was a pure byor he was!
3. Remember when she streaked naked through the convent?? What a byor!