1. short twentieth century - Noun
2. Short twentieth century - Proper noun
short twentieth century
(history, specifically) The period between 1914 and 1991, from the beginning of World War I to the fall of the Soviet Union. [from 1990s]
short twentieth century (plural short twentieth centuries)
(history, generally) Any period of years defined by significant historical events falling within the 20th century (1 January 1901 to 31 December 2000).