duodecimate /ˌdjuːəʊˈdɛsɪmeɪt/verb 2noun 1forms 1 verb2 •(rare) To kill one twelfth of a group of people, especially by lot.The French squadron…opened fire at a distance far beyond the range of our rifles, and the carnage in our ranks was fearful. We were being gradually duodecimated. — 1868 •(rare) To divide into twelfths; to divide duodecimally.He has duodecimated his difficulties by choosing twelve boy “heroes.” — 1899 noun1 •(rare) Synonym of duodecimvirate: a group of twelve.We affirm, that to all eternity the apostles are to be twelve, among all the redeemed, a conspicuous, glorious, unassociated duodecimate. — 1851 formsduodecimated