A century or a centennial
100 anniversary.
Our town is having a centennial celebration for the hundredth anniversary of the founding.
A one hundredth anniversary is called a centenary,centennial
Yes, the sesquicentennial celebration marks the 150th anniversary of the company's founding.
centenary, centennial
Year is to Anniversary as Month is to "Monthiversary." The term "Monthiversary" is a portmanteau of "month" and "anniversary" and is commonly used to refer to the monthly celebration of a significant event or milestone. Just as an anniversary marks the yearly recurrence of an event, a Monthiversary marks the monthly recurrence of an event.
The difference is that century means one-hundred of years while centennial the 100th anniversary or birthday, or the hundredth anniversary of something, or a celebration held to mark the anniversary.... it's really confusing and if you don't get it try reading it over and over again and really think about it ;)
Sesquicentennial
The one hundredth anniversary of something.
bicentennial
centennial, centenary
A silver anniversary or celebration is completion of 25 years.A golden anniversary or celebration is completion of 50 years and the Diamond celebration is completion of 70 years ( some celebrate in 60/65 years completion) Addition: Diamond celebration used to refer (and still can) to the 75th anniversary, but currently often refers to the 60th anniversary. Platinum is the 70th anniversary.