Variations on the word are aliasing, the present tense verb form, and aliaser, referring to the actual person hiding behind their false name, whose identity will never change (in online situations).
Aliasing is frowned upon because people may think that you're a new person, or in small-community games where everybody knows everybody, possibly even cheating. People like to get to know a regular client's personality, and develop a friendship or rivalry with them. Aliasing disrupts this, since you never know if you're talking with friend or foe.
I think Bob is here, but he's aliasing.
The aliaser is aliasing if he uses an alias.
-word origin: Kennedy High School in Silver Spring, Maryland circa 2001-2002
1. A person whose existence very few others know or care about
2. Someone who is not recognized socially to the extent that others do not even know that the person in question even exists
In some cases, this name can get you into serious trouble. Keep it anyway.
Brad: Whoa! Slow down ho! It's Blakk. Victoria Blakk.
Random Skank: How awesome! I wanna make babies with you!
Brad: *runs away*
Other examples for an alias include but are not limited to: Ted, Bob, and Jill.
Girl #2: YES Vaughn is so hott!
Everyone else in vicinity: SHUT UP ABOUT ALIAS!