tredecennial

Etymology
+ 🇨🇬 or + 🇨🇬

Noun

 * 1)  A  of  years.
 * 2) * 1952, Proceedings of the IInd International Congress on Criminology III: “Psychiatry, Psychology, Psychoanalysis”, page 65
 * The tredecennial covered by the period of the survey was in a sense a most remarkable one; for it includes, with almost exact divisions, three significant sub periods: the prewar, the war and the post-war.