Hey, is the guy in the warehouse a ninja?
Nah, he's a total velten, man.
The previous definition was submitted as an evil plot to defame the name Velten, by a derranged pirate who's family was killed by a Velten, thus proving that a Velten is indeed ninja.
The true definition of Velten is one who is there but not there; one who is RIGHT BEHIND you, but cannot be seen or detected; one who is sneaky sneaky, and will cause target self injury and possible heart attack.
Be sure to look for any Velten's on the ceiling when entering a dark room.