This is the definition some of my Korean friends gave me.
Pro : A person who has great potential at becoming a clever strategist during battles and uses ingenuity to outmaneuver enemies. It doesn't matter if they're new or if they're long-time players. Anyone that is willing to learn, show his regards on his side of respect, and is willing to be the best, is in our (me and my friends) minds, a certain professional. Besides, even some of the "pros" complain WAY too much. I don't want to name them, but there are some "pros" as people would say, that complain about lags, lags, lags, luck, luck, luck. Those guys aren't exactly pros. Even if they win, I know some who would purposely say lags just to drag others down, lower their strengths. A pro, simplified, is a person who accepts losing with no complaining. If they even say the word "lags", I can almost immediately know, that they like to brag.
Noob : This word irritates me. Imo, a noob is an ignorant person that refers to others to take his/her own blame. If the other person spams, and this one person refers to the other guy as a "noob" or "spammer", his talents are far inferior. One, because he can't do anything to the spammer, Two because he can't BEAT the spammer, Three, he's trying to make himself seem superior in intelligence, although it's pretty straightforward how insignificant his maneuvers are, and those people who complain countless times even to the point where other people would beat the literal life out of them. I would hate fighting a person who says "Damn, lags." (Sorry, profanity.) every few seconds. Anyone who complains or gives the blame to others (in a serious, annoying choice of words, not in a friendly tone such as two friends calling each other " NOOB LOL!!!!!". I mean imbeciles who literally go "F*CKING NOOB. STOP RUNNING." That's a noob, in my views.