2) Someone who is aware of twitter, knows how it works, but is still in some way mentally deficient with their use of it.
3) Worthless twitter posts (a phrase which may or may not be redundant).
A: What's a tweeter?
B: It's like a messaging facebook thing. You use it to post toots.
C: Hey, I got Twitter! But it says I can only post 120 words at a time.
E: "Hello World. I am sitting on the couch.@Urbandictionary 6 minutes ago
F: "Stop being Tweetarded!!1@Twilight4Evarr 1 minute ago