Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

dŭŏdĕcim, card. num. [duo-decem], twelve, Plaut. Ep. 5, 2, 10; Cic. Rep. 2, 17; Caes. B. G. 1, 5, 2 et saep.
So, duodecim (and more freq. XII.) Tabulae, the laws of the Twelve Tables, Cic. Off. 1, 12; Quint. 5, 14, 18; Varr. L. L. 5, § 22 Müll. et saep.; called also absol.: duodecim (or XII.), Cic. Leg. 2, 23 (repeatedly); id. Off. 3, 16 al. (v. Wordsworth, Fragm. and Spec. pp. 253-265).