lustrum

[ luhs-truh m ]

/ ˈlʌs trəm /

Also luster; especially British, lustre. a period of five years.

Roman History. a lustration or ceremonial purification of the people, performed every five years, after the taking of the census.

Origin of lustrum

1580–90; < Latin lūstrum; cf. luster¹

One of the British novels with the highest sales hopes before Christmas is Lustrum by Robert Harris.

The Best of Brit Lit |Peter Stothard |September 30, 2009 |DAILY BEAST
The lustrum which saw the birth of Robert Browning, that is the third in the nineteenth century, was a remarkable one indeed.

Life of Robert Browning |William Sharp
It makes a lustrum in the Senate, and an era in the history of the Antislavery cause.

Charles Sumner; his complete works, volume 6 (of 20) |Charles Sumner
They are charged as a result with making the lustrum, a great ceremony of purification which occurs every five years.

History Of Ancient Civilization |Charles Seignobos

Nor had this lustrum of fierce contention wrought less upon his heart and intellect.

The Collected Works of Ambrose Bierce, Vol. II: In the Midst of Life: Tales of Soldiers and Civilians |Ambrose Bierce
Let us sit with our hands on our mouths, a long, austere, Pythagorean lustrum.

Phrases for Public Speakers and Paragraphs for Study |Compiled by Grenville Kleiser

lustrum

/ (ˈlʌstrəm) /

a period of five years

C16: from Latin: ceremony of purification, from lustrāre to brighten, purify