Upper-Intermediate (B2)
IPA: /kwɪnˈsɛnˌtɛn.i.əl/
KK: /kwɪnˌsɛnˈtɛn.i.əl/
Definition
Relating to a period of five hundred years or a celebration marking this time span.
Example
The city held a quincentennial celebration to honor its founding.
Conversation

Did you hear about the quincentennial celebration happening next year?

Yeah, I read something about it! It seems like a big deal.

I can't believe it's been five hundred years already since that event.

I know, right? We should definitely go and check it out!
Synonyms & Antonyms
Definition
A celebration or event that marks the 500th anniversary of something.
Example
The city held a grand festival to celebrate its quincentennial.
Conversation

Did you hear about the big party for the quincentennial celebration next year?

Yeah, I can't believe it's been five hundred years already!

I know, right? We should definitely go and check out the events they have planned for the quincentennial.
Root Explanation
Quincentennial is formed from "quinque" (meaning five) and "centennial" (from "centennium", meaning a hundred years). The word refers to a celebration or commemoration of five hundred years.
Memory Tip
Think of 'five' ('quinque') and 'hundred years' ('centennial') to remember that quincentennial means a celebration of five hundred years.
Visually Confused Words
sesquicentennial
quadricentennial
bicentennial
centennial
tricentennial