twentieth /ˈtwɛn.ti.əθ/noun 2adjective 1forms 1 noun2 •A person or thing in the twentieth position. •One of twenty equal parts of a whole. adjective1 •The ordinal form of the number twenty.“A shift from jus soli to jus sanguinis has been witnessed in Asia in the course of the twentieth century,” wrote Olivier Vonk at the Maastricht Centre in a 2017 paper. — 2021 formstwentieths