In this article in Dutch, I wrote about elected Words of the Year which I suspect do not really exist, but are proposed as an psychological experiment, based on the expectation that nobody has the guts to admit they have never heard of a word so well-known that it is even proposed as a candidate to be chosen as Word of the Year.
But I have. The guts, I mean, not heard.
The article is also about a different kind of ghost words (Dutch: spookwoorden), non-existent words that dictionary editors used to put in dictionary hoping to detect copyright infringement. The example is the word “honduree”, which has been in some editions of the famous Van Dale dictionary, supposedly referring to some sort of plastic sheet to separate slices of luncheon meat. But other than those dictionary entries, no occurrences of the word were ever found.
I was reminded of this when seeing this question in Usenet group sci.lang, by Hen Hanna. I wasn’t aware of the name Skeat, but from Wikipedia we can learn that Walter William Skeat (1835–1912) was the one who coined the term ‘ghost word’.
The examples Professor Skeat is reported to have mentioned, are more like unintentional errors than deliberately fictitious entries. They reminds me of the words zenith and azimuth (that article too is in Dutch; update December 2020: also in Interlingua). Zenith stems from misreading a transcription of an Arabic word, ‘samt’, as ‘sanit’!
And yes, the international word ‘gas’ was first coined in Dutch, with Greek ‘chaos’, and perhaps also Dutch ‘geest’ in mind: Wiktionary.