sesquicentennial

American  

[ses-kwi-sen-ten-ee-uhl] / ˌsɛs kwɪ sɛnˈtɛn i əl /

adjective

1. pertaining to or marking the completion of a period of 150 years.

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noun

1. a 150th anniversary or its celebration.

sesquicentennial British  

/ ˌsɛskwɪsɛnˈtɛnɪəl /

adjective

1. of or relating to a period of 150 years

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noun

1. a period or cycle of 150 years

2. a 150th anniversary or its celebration

Other Word Forms

• sesquicentennially
  adverb

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Etymology

Origin of sesquicentennial

An Americanism dating back to 1875–80; sesqui- + centennial

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Example Sentences

See Examples For:

sesquicentennial

The sesquicentennial of MLB’s first game comes on the heels of several rule changes designed to address the sport’s glacial pace.

From The Wall Street Journal ● Apr. 21, 2026

It’s the sesquicentennial of Western Australia, and everyone on Tony and Judy’s cul de sac is excited.

From Los Angeles Times ● Oct. 2, 2024

But Bacevich offers nothing from Calvin Coolidge’s luminous address on the sesquicentennial of the Declaration of Independence.

From New York Times ● Apr. 1, 2020

By 2009, at the sesquicentennial, the country had seemingly changed, with Barack Obama its first African American president.

From Washington Post ● Oct. 13, 2019

It was on the engine at the time of the Carlisle sesquicentennial but disappeared by the time of the St. Louis exposition.

From The 'Pioneer': Light Passenger Locomotive of 1851 United States Bulletin 240, Contributions from the Museum of History and Technology, paper 42, 1964 by John H. White

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