What is Noob-rush?
1.
When a (large) group of lower-level players attack one target at the same time, overwhelming them with superior numbers, AND the element of surprise.
Veteran *Walking alone down the street*
50 Newbies *Pour out of the alleyway and start punching the Veteran until he dies, quickly loot his corpse, and flee*
Veteran *Arrives at his corpse after being rezed* "Wtf! I can't believe I was just noob-rushed!"
See