Cen‐ten″ni‐al (?), a. [L. centum a hundred + annus year.] 1. Relating to, or associated with, the commemoration of an event that happened a hundred years before; as, a centennial ode.
2. Happening once in a hundred years; as, centennial jubilee; a centennial celebration.
3. Lasting or aged a hundred years.
That opened through long lines
Of sacred ilex and centennial pines.
Longfellow.