In First-Person shooters, where a player (specifically a noob, hence "noob toobing") kills players using only grenade launchers, RPGs, Rocket launchers, or any other weapon considered cheap. While it is ok to do this once in a while, it considered just not right to do repeadedly.
A Noobtoob is someone who is really stupid, and misspells common words, also someone who cant speak properly or use the right context of english.
(also someone who spells tube toob)
e.g. (lucas said)How do i spell the word elf?
e.g. (lucas said)it saids plz click sex so i did and i say i didnt
e.g. (Steve wrote) you place the sodium bicarbonate in the test toob