adjective oc·ten·ni·al \(ˈ)äk¦tenēəl\

Definition of octennial

  1. 1 :  happening every eighth year

  2. 2 :  lasting for a period of eight years

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Origin and Etymology of octennial

Late Latin octennium period of eight years (from Latin oct- —from octo eight—+ -ennium, from annus year) + English -al — more at eight, annual

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a rounded knoll or a ridge of ice

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