decimus or (older) decumus, adj. decem, the tenth (of a series): mensis, T.: hora diei: septuma (dies) post decumam, i. e. the seventeenth, V.: legio, Cs.: unda, O.: cum decumo efficit ager, i. e. tenfold.

—The tenth (part; i. e. one of ten equal parts): vix decumā parte die reliquā, S.: pars praedae, L.