Any grenade launcher attachment used in Call of Duty 4 Modernwarfare, employed by n00bs of the highest caliber.

The name given, by players of the game CoD4, to the assault rifle mounted grenade launcher do to the fact that it is seen as requiring little skill to use and the fact that it is, in fact, a tube.

Also, the use of said grenade launcher.

The M203 rifle mounted grenade launcher used by newcomers to the videogame Call of Duty 4: Modern Warfare, specifically its online multiplayer. while requiring no skill or effort, this weapon also barely hurts the user while completely obliterating any who get in its path. This is seen as a cheap weapon only acceptable for use by the worst of players at this particular game.

Any grenade launcher, be it an M203 or a GP-30, used on a video game. Specifically online on Call of Duty: Modern Warfare or Modern Warfare 2. It requires almost little or no skill to effectively get kills with it. Just aim in a general direction of wherever you think the enemy might be, and it'll get the job done without giving your enemy time to avoid it or retaliate.

Surprisingly, despite its name, it's not primarily used by noobs, or newcomers to the game. It's actually used more by assholes that are well into the game already but only use it to piss off their opposing team. And unfortunately, they usually do succeed in pissing off their enemy which could (and normally does) result in the enemy team changing their class to a noob tubing class while saying something like "Oh you wanna noob tube bitch? I can do it too", and that results in an entire game session being nothing but noob tubes and/or RPG's, depending on who's in the game.

Highly disliked by the majority of the gaming community. Avoid noob tubing at all costs to ensure that you don't start a tubing chain-reaction.

A gaming term for an under-mounted grenade launcher such as the M203 or any other kind of launched explosive (RPG, Thumper, etc) used in first person shooter games such as Call of Duty: Modern Warfare 2 or Battlefield: Bad Company 2. Use of such a weapon to get kills is considered 'cheap', since it requires very little skill to use. 'Noob' is a term for a newcomer to a game, and is used as an insult in gaming communities.

Reference to a grenade launcher type weapon featured in several warfare silmulation games, both online and offline.
Takes very little skill to use and can kill whole groups of enemies with a single indirect hit, yet the explosion needs to be fairly close.

To be used liberally against elitist gamers who play games all day because they can't get jobs and whenever they can't win they start crying. Much amusement to be had reading their abuse.

Usually refers to the grenade launcher in Call of Duty 4 due to it's high power and wide kill radius, and especially it's easiness to use.