'Noob' just means new or inexperienced, or in other words it's a rude way of saying "I'm better than you" or "you're bad at this game". It isn't something to take insult to, since in literal terms everybody has been a 'noob' at some point, and whether you currently are one or not, you can only grow better and more experienced. It was only added to the swear filter to reduce bad sportsmanship, not because it's offensive, similar to how 'rekd' was recently added to the swear filter.
Try to ignore them since it doesn't mean anything offensive, and remember to say gg at the end of every game for a free 1xp :)
/locked