The word "twentieth" refers to something that is in the twentieth position, place or rank. It can also refer to a time period that occurred during the 20th century (1901-2000).
I will be greatly surprised if her works are not soon recognized as some of the best writing in twentieth century American literature. (bookbrowse.com)
The breed almost died out before being revived in the early twentieth century by breeders in its homeland. (dailypuppy.com)
Many of the pieces included in this exhibition are considered pivotal works of late twentieth century art. (locksgallery.com)