tricentennial

[trahy-sen-ten-ee-uh l]

adjective

pertaining to 300 years or a period of 300 years.
marking the completion of such a period: a tricentennial celebration.

noun

a 300th anniversary or its celebration.

Also tercentenary, tercentennial.

Origin of tricentennial

First recorded in 1880–85; tri- + centennial
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019