Someone who is new to youtube. This can include anyone who has just started posting videos, commenting, etc.
Jon: Hey Stephen, this video is awesome. Have you seen this guy before?
Stephen: No, I think he's a newtuber.
Stephen: No, I think he's a newtuber.
by *Sylvia January 7, 2008
Get the newtubermug. 
Get the newtubemug.