term used in fps(first-person shooter), a person that seems to be good and cocky in pubs(public games) but when it comes to matches etc. they cant back their noob asses up with skill.
A:You got 0wn3d in the face son!
B:ok lets scrim
after the scrim
A:man i was lagging
B:watever you pub scrub..uninstall n00b!