look up any word, like sounding:
 
1.
A person who has exhausted all ninety-nine possible weeks of unemployment benefits.
"Tier 5 to Survive" has become the rallying cry of the "ninety-niners", those unemployed who have found themselves jobless for the longest period of time and have nearly or already exhausted all ninety-nine possible weeks of unemployment benefits.
by paulchristenson December 19, 2010
 
2.
A person who moved out to San Francisco during the Internet gold rush at the turn of the 21st century, roughly in the year 1999.

It is a play on the term "Forty-Niners," which refers to people who moved out to San Francisco during the gold rush around the year 1849.
Yes, I did come to San Francisco in August of 1999 to work for pets.com, but I find the term "ninety-niner" offensive.
by NYCDavid July 22, 2012
 
3.
A Man who Engages in Sexual Intercourse With Other Men
Usually This Term Refers To All Nazis.
Hey Look at Those two Guys kissing,they must be Ninety-Niners
by Corey Bloom October 22, 2006