trĭnoctĭum

I. a space of three nights, three nights: continuum, Fab. Pict. ap. Gell. 10, 15, 14; cf. Gell. 3, 2, 13; Val. Max. 2, 4, 5; Aus. Idyll. 11, 34; Amm. 14, 2, 13.