10 Things We Learned From Triple H's Wikipedia: Fact Or Fiction
5. He Heard Shane McMahon Say "D-Generation X" First
Wikipedia credits Vince Russo and New York Post journalist Phil Mushnick (a well-known WWF critic) for coming up with the name "D-Generation X". Triple H took a red pen and dashed a big red 'X' right through that idea. He says he first heard the name from a rather unlikely source.
Shane McMahon.
Triple H overheard Shane talking to someone backstage in 1997 about a recent Bret Hart promo during which the Canadian had called Shawn Michaels' new gang a "bunch of degenerates". As he explained the skit, Shane accidentally coined the phrase "D-Generation X", and the guys liked it so much they decided to use it.
McMahon was trying to explain that the rebellious group represented Generation X, but did so with an anti-authority spirit that made them "D-Generation X". That was the very first time that Triple H heard the phrase used.