·adj Lasting or aged a hundred years.
II. Centennial ·noun The celebration of the hundredth anniversary of any event; a centenary.
III. Centennial ·adj Happening once in a hundred years; as, centennial jubilee; a centennial celebration.
IV. Centennial ·adj Relating to, or associated with, the commemoration of an event that happened a hundred years before; as, a centennial ode.