Dictionary
sem•i•cen•ten•ni•al
Pronunciation: (sem"ē-sen-ten'ē-ul, sem"ī-), [key]—
adj.
of or pertaining to a fiftieth anniversary.
—
n.
1. a fiftieth anniversary.
2. the celebration of this anniversary.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.