lustrum Meaning, Definition & Usage

  1. noun a period of five years
  2. noun a ceremonial purification of the Roman population every five years following the census

WordNet

Lus"trum noun
Etymology
L. Cf. 2d & 3d Luster.
Wordforms
plural E Lustrums L Lustra
Definitions
  1. A lustration or purification, especially the purification of the whole Roman people, which was made by the censors once in five years. Hence: A period of five years.

Webster 1913