1. The decade from 1990 to 1999
   "The World Wide Web became publicly available in the nineties";
   - 1990s
    
2. The decade from 1890 to 1899
   "The Klondike Gold Rush occurred in the nineties";
   - 1890s
    
3. The time of life between 90 and 100
   "She celebrated her mid-nineties by skydiving";
   - mid-nineties

1. The cardinal number that is the product of ten and nine
   "She scored ninety on her test";
   - 90, XC

Type of: decade, decennary [archaic], decennium, large integer, time of life

Part of: age, eld, geezerhood [informal], old age, years

Encyclopedia: Nineties