Here a twit means an idiot as well.

Hi... Twit Meaning and Definition 1. (v. t.) To vex by bringing to notice, or reminding of, a fault, defect, misfortune, or the like; to revile; to reproach; to upbraid; to taunt; as, he twitted his friend of falsehood.

A new word only in the world of Cosmopolitan & Perez Hilton. ;) Ah, acronyms! The problem with acronyms is that at some point you need to explain the meaning. So they're only properly good for expressing technical jargon shorthand (eg. 'laser' is an acronym), or for amusement... like your example. 'Twit' means exactly as Jura said... an idiot. While you can say it stands for "Teenage Women In Their Thirties", you're also hinting that these women are acting like idiots (twits) and should grow up. ;) Same meaning for Twitter... the double meaning of calling a Twitter user a "twit" is well-recognised. :D

twit - its creating a message in Twitter Twit or Twitting :)

Yea comes from Twitter =)