cen·ten·a·ry 
(sĕn-tĕnə-rē, sĕntə-nĕr′ē)
(sĕn-tĕnə-rē, sĕntə-nĕr′ē)adj.
1. Of or relating to a 100-year period.
2. Occurring once every 100 years.
n. pl. cen·ten·a·ries
1. A 100-year period.
2. A centennial.
[Latin centēnārius, of a hundred, from centum, hundred; see dek in the Appendix of Indo-European roots.]