quindĕcim, num. adj. [quinque-decem],
fifteen : QVINDECIM PONDO, Lex XII. Tab.: quindecim miles minas dederat, Plaut. Ps. 1, 1, 51; 1, 3, 112; Hor. C. S. 70: dies circiter quindecim, Caes. B. G. 1, 15; Ap. Mag. p. 304, 33.
quīndecim or XV numadj. quinque+decem, fifteen : dies, Cs.: annos XV natus: evocat ad se Massiliā ...
An Elementary Latin Dictionary