The Members
W. Axl Rose
Axl was born as William Rose in Lafayette, IN, USA. When he was two years old his father left his family. Some time later his mother, Sharon, remarried to a Stephen Bailey. Then Axl's name was William Bailey. He didn't know that Stephen wasn't his real father until he was 17 and found out that his real name, William Rose, to which he changed.
"Axl" was the name of a band that he and Izzy had back in Indiana. Later he took that as his name, and was then called Axl Rose. In 1986 he changed his name once again, this time to W. Axl Rose. He included the "W" "because William was an asshole".
Slash
Slash's birth name is Saul Hudson. He got the nickname "Slash" in his teens by a friend who said that: "Slash was always in a hurry, zipping around from one thing to another."
Duff McKagan
Duff's birth name is Michael McKagan. His family lived in an Irish neighbourhood and a lot of kids were called Michael around, so therefore he got a nickname, and that was Duff. I don't know why it became Duff though.
Izzy Stradlin
Izzy's birth name is Jeffrey Isbelle. I have no idea where the nickname "Izzy" comes from.
Steven "Popcorn" Adler
There's nothing "strange" known about his name. His nick-name, "Popcorn", was because (since he dyed his hair) you could always see his roots.
Dizzy Reed
Dizzy's birth name is Darren Reed.
Matt Sorum
Matt's birth name is Matthew Sorum. Matt is a common nick-name for Matthew in English.
Gilby Clarke
Gilby's birth name is Gilbert John Clark. Later he added an "e" to his last name.
The Solo Bands
Neurotic Outsiders
The singer/guitarist of Neurotic Outsiders, Steve Jones came up with this name. They were originally called "Neurotic Boy Outsiders" but changed because it was too long.
Slash's Snakepit
This band was originally called just "Snakepit" after Slash's home studio. When their album, "It's Five O'Clock Somewhere" was going to be released, Geffen said that to gain recognition, "Slash's" had to be added. If not, they wouldn't support a tour.
Slash's Blues Ball
Slash originally wanted to call this band "Slash's Blue Balls". But they had to change when they were going to tour.