Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. quintus (old form quinctus, Plaut. Trin. 2, 4, 123), a, um, num. adj. [quinque], the fifth: quarta invidia, quinta ambitio, Plaut. Pers. 4, 4, 8: locus, Cic. Inv. 1, 53, 102; 1, 55, 107: natura, id. Tusc. 1, 17, 41: quinta pars, quintessence, essence, Hor. C. 1, 13, 16: quinto mense, quinto die, Liv. 31, 7.
Advv.