of or ending a period of 50 years
Origin of semicentennialsemi- + centennial
a 50th anniversary or its commemoration
Marking the 50th anniversary of an event.
A 50th anniversary or its celebration.
- Occurring every 50 years
- A 50th anniversary.
- The city celebrated its semicentennial last year.
semi- (“half") +"Ž centennial (“of 100 years")