1) Lustral 1) Occurring every five years 2) Of a lustrum 3) Of or lasting for five years 
• (a.) Occurring once in five years, or at the end of every five years; also, lasting five years. A quinquennial event.
Quin·quen'ni·al adjective [ Latin quinquennalis and quinquennis ; quinque five + annus year. See Five , and cf . Biennial .] Occurring once in five years, or at the end of every five years; also, lasting five years. A quinquennial event. 
of or lasting for five years. · occurring every five years.