You have spoken. Earlier this week, I asked for nominees for the next new NOOB, and you chose (narrowly) twee. So twee ’tis.
As for definition, I can do no better than the most popular entry at urbandictionary.com:
Something that is sweet, almost to the point of being sickeningly so. As a derogatory descriptive, it means something that is affectedly dainty or quaint, or is way too sentimental. In American English it often refers to a type of simple sweet pop music, but in British English it is used much more widely for things that are nauseatingly cute or precious. It comes from the way the word sweet sounds when said in baby talk.“Belle and Sebastian are the Beatles of twee.”
The OED gives the etymology of twee as “infantile” pronunciation of sweet, dates it to 1905, and offers this definition: “Originally: ‘sweet’, dainty, chic. Now only in depreciatory use: affectedly dainty or quaint; over-nice, over-refined, precious, mawkish.”
Americans may find [choreographer Ronald] Hynd all too twee (look that one up in your Anglo-American dictionary). (Anna Kisselgoff, New York Times, April 18, 1982)/[Mari Eastman’s] paintings are pretty and a bit twee, and I never found them very interesting, until now. Culture Monster [Los Angeles Times blog], April 21. 2011)