lustral

/L AH1 S T R AH0 L/
adjective
  1. 1

    Of or pertaining to (ritual) purification.

    โ€œlustral daysโ€

  2. 2

    Of or relating to a lustrum, or period of five years.

    โ€œa lustral cycleโ€

Source: https://en.wiktionary.org/wiki/lustral