Lewis Short
(adjective) : per-dĭŭturnus, a, um
* That lasts a very long time, very lingering or protracted (rare but class.), Cic. N. D. 2, 33, 85 (but Cic. Sest. 27, 58 Halm and B. and K. read diuturnum).
Charlton T. Lewis, Charles Short, A Latin Dictionary