S / septŭennĭum
noun

septŭennĭum

gen. septŭennii · gender neuter · decl. 2nd
septuennis
a period of seven years
a period of seven years, Fest. p. 347 Müll.— Collat. form septennĭum, Prud. ap. Tetrast. 6; Vell. 2, 31, 2 Haase.