Bicentennial

Adjective

 * 1) Relating to the 200th anniversary of an event or happening.
 * 2) Occurring every two-hundred (200) years

Noun

 * 1) The 200th anniversary of an event or happening.
 * The US bicentennial in 1976 was celebrated greatly because the economy happened to be good.

Thesaurus
anniversary, annual holiday, bicentenary, biennial, birthday, bissextile day, cental, centare, centenarian, centenary, centennial, centennium, centigram, centimeter, centipede, centistere, centred, centref, centrev, centumvir, centumvirate, centurion, century, commemoration, cwt, decennial, diamond jubilee, golden wedding anniversary, gross, hecatomb, holy days, hundred, hundredweight, immovable feast, jubilee, leap year, long hundred, name day, natal day, octennial, one C, quadrennial, quasquicentennial, quincentenary, quincentennial, quinquennial, septennial, sesquicentenary, sesquicentennial, sextennial, silver wedding anniversary, tercentenary, tercentennial, tricennial, triennial, wedding anniversary