Themken: I followed that link and the first word I tried was not even recognised as a proper word; I guess the Americans do not use it. I managed to guess the word in three tries, which I think was very lucky. Quite a nice little game. I wish there would be a British English version too. Maybe someone knows of one.
You can blame the New York Times for it. The original game included British spelling variations, and a bunch of other words the paper found objectionable.
"We are updating the word list over time to remove obscure words to keep the puzzle accessible to more people, as well as insensitive or offensive words," the Times said in a statement provided to ABC News' Michael Slezak.
Fibre is given as an example of an obscure or offensive word worthy of removal.