| Answer | Crossword Clue |
|---|---|
| centennially | CENTENNIAL, recurring every hundred years; lasting a hundred years |
| centennial | recurring every hundred years; lasting a hundred years / a hundredth anniversary |
| bicentenary | happening every two hundred years / a two hundred year anniversary also BICENTENNIAL |
| bicentennial | happening every two hundred years / a two hundred year anniversary also BICENTENARY |
