Superiority :

Seniority : the fact or state of being older or higher in rank or status than someone else.
Juniority : for or denoting young or younger people.

Urbanity : urban life.
Posteriority: chiefly Anatomy further back in position, of or nearer the rear or hind end.
Inferiority : the condition of being lower in status or quality than another or others.
Superiority : excellence, eminence, transcendence, mastery.

Then, the antonym of Superiority is Inferiority.