semicentennial
/ˌsɛmiˌsɛnˈtɛniəl/
noun
- A 50th anniversary or the celebration of it.
- The museum published a special book to mark its semicentennial.
- The town held a parade and fireworks for its semicentennial.
- My grandparents are planning a big party for their company's semicentennial.
adjective
- Relating to a 50th anniversary or a period of 50 years.
- The semicentennial celebration included speeches from former leaders.
- They released a semicentennial edition of the classic novel.
- The park was renovated as part of the city's semicentennial project.