What does Omega mean in a pack?

The omega is the lowest ranking wolf in a pack. There is usually only one omega in a wolf pack (I think). The omega is picked on by other members of their pack. Omegas are important because the other wolves can pick on them to relieve stress and settle arguments, therefore reducing tenseness and grudges in the pack. Just a personal theory, but the omega might also keep the pups of the pack busy and happy by giving them attention so the mothers can have free time.