semicentennial

American  

[sem-ee-sen-ten-ee-uhl, sem-ahy-] / ˌsɛm i sɛnˈtɛn i əl, ˌsɛm aɪ- /

adjective

1. of or relating to a fiftieth anniversary.

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noun

1. a fiftieth anniversary.

2. the celebration of this anniversary.

semicentennial British  

/ ˌsɛmɪsɛnˈtɛnɪəl /

adjective

1. (prenominal) of or relating to the 50th anniversary of some event

2. occurring once every 50 years

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noun

1. a 50th anniversary

Etymology

Origin of semicentennial

First recorded in 1855–60; semi- + centennial

Example Sentences

As the program celebrates its semicentennial, we asked readers to share their favorite P-Patch memories.

From Seattle Times

To mark the 50th anniversary of saving Pike Place Market, the Market’s traditional fall festival will transform into a semicentennial celebration of the landmark 1971 initiative.

From Seattle Times

This season, Wolf Trap in Vienna, Va., returns to the scene to celebrate the semicentennial of the Filene Center.

From Washington Post

Research reveals that the story long told about Hopkins as a Quaker and abolitionist, descended from men who freed their slaves, was adopted just after the university celebrated its semicentennial in 1926.

From Washington Post

Now, on the occasion of the Verrazano’s semicentennial, a group of cyclists, transportation advocates and residents on both sides of the bridge are leading a grass-roots-and-pavement campaign to add a pedestrian path.

From New York Times