Lucubration

No article on Wikipedia??  No surprise actually.

https://en.wikipedia.org/wiki/Lucubration

 Latin lūcubrātiō (“nighttime study”), from lūcubrō (“work by artificial light”), from lūx (“light”).

At least there is a link to wiktionary.  But even so, Lightsaber and Wookie have extensive articles, even multiple articles explaining and giving examples.  And neither one of those words describe an actual thing. 

 Sir Arthur Conan Doyle, The Disintegration Machine‎^[1]:

'You have been good enough to allude to me in one of your recent lucubrations,' he said, shaking the paper at me