Used for purification

• Every five years
• Every five years, there's passion with return of the French right
• Desire sex really regularly (every five years)

Wiktionary Word definitions in Wiktionary
a. 1 Of or pertaining to (ritual) purification 2 Of or relating to a lustrum, or period of five years.

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
"pertaining to purification," 1530s, from Latin lustralis , from lustrum (see lustrum ). Hence, also, "every five years" (1781).

Wikipedia Word definitions in Wikipedia
Lustral may refer to: Sertraline (also known as "Lustral"): an antidepressant Lustral (band) : an electronic music band