trīdŭānus

a, um, adj.

triduum

I. lasting three days, of three days' continuance (post-class.): spectaculum, App. M. 10, p. 247, 27: jejunia, Hier. Ep. 54, 10: funus, Paul. Nol. Carm. 12, 207.
Lewis & Short
A Latin Dictionary, 1879
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