undēquinquāgēsĭmus, a, um, num. adj. [undequinquaginta],
the forty-ninth dies, Cic. Imp. Pomp. 12, 35; Vell. 2, 17, 3.
ūndēquīnquāgēsimus (-gēnsimus) numadj. undequinquaginta, the forty-ninth : dies. ...
An Elementary Latin Dictionary