A player who is, or acts as though he is, new to the game. Not understanding the 'finer' points, using simple tactics and, all too often, irritatingly having fun regardless.
Named for, well, being new. Even though they need not be. The term (and various leet spellings of it) is used as an insult. This is unhelpful.
A casual player. Though they usually understand the subtle points of a game they don't often get to use them. Their overall skill can often be very high, though it is unfairly derided by Clanners. ObstinateJimmy? is a wonderful term for this, which I shall adopt :)
Named for their habit of playing on public servers, rather than in organised tournaments.
A 'serious' player, they devote time to the game deliberately - willing to absorb quite large amounts of WorkPlay? in order to become better at the FunPlay?. Usually devoted more to winning than having fun. Often spends a lot of time boasting about their skill. Can sometimes back that up.
So named because they are usually members of a team, squad guild or clan. Or multiple such.
Someone who has, by and large, dropped out of active play. They know and understand the game in whatever depth the game has - and spend their time trying to find new depths and strategies rather than honing their skills in the existing ones. These players are usually the ones responsible for revitalising the game by introduing whole new concepts. They also bitch and moan a lot about how bored they are :)
Naming is obvious.
Someone whose enjoyment of the game lies almost wholly outside of the game. They get their fun from annoying other people using whatever means they have at their disposal.
They cheat, they spam, the find ways to force the game to make rude noises, they betray their team... whatever it takes to get a reaction.
They are often casual players in a non-casual setting who cannot keep up with the non-casual players, and so take to cheating and other activities to get notice rather than overtaken.
Naming is *probably* from JeffMinter games. I'm pretty sure if you look up the archive of alt.game.halflife.tf-classic you'll find the genesis. The group was looking for an alternative to 'newbie' to differentiate between someone who didn't know what they were doing, and someone who knew perfectly well how annoying it was...