They end a century

• Neckwear for a full baseball team?
• 19th century's "naughty" decade
• Last decade of a century
• "Gay" decade
• and the decade Beck blew up
• Period when Stone Temple Pilots took off
• Gay time

Wiktionary Word definitions in Wiktionary
alt. 1 (plural of ninety English) 2 The decade of the 1890s, 1990s, etc. n. 1 (plural of ninety English) 2 The decade of the 1890s, 1990s, etc.

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
nineties \nineties\ n. pl. The decade from 1890 to 1899; as, the gay nineties. The decade from 1990 to 1999; as, they spent a ton of money to solve the Y2K bug in the nineties. The time of life between ages 90 and 100. Syn: mid-nineties.

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1857 as the years of someone's life between 90 and 99; from 1848 as the tenth decade of years in a given century; 1849 with reference to Fahrenheit temperature. See ninety .\n\nMany still live who remember those days; if the old men cannot tell you the ...