A friendly, slightly derogatory term used to tease someone who is inexperienced or makes a rookie mistake, especially, but not exclusively, while playing video games.
Something Michael Scott from The Office (Steve Carell) believes to be a word. He spells it in Jim and Creed's game of scrabble in episode 26 of season 5.
That noscrub works way better than tissues for getting my nose clean.
A lightly used insult referring to someone who is being a noob and you are calling them a scrub.
Person 1: "Hey guys! In Super Smash Bros, throw off the ledge to down smash spike is a true combo!"
Person 2: "Your such a nubscrub. That's impossible."