The first constructed international auxiliary language (world-wide helping language) to really gain traction. Designed by a German priest, Johann Martin Schleyer, who felt God had told him to create an international language, Volapük's vocabulary is actually heavily based off of languages like English, French and German, and the language would have been extremely simple, had it not been for the inclusion of so many vowels and about 300x as many suffixes (future changes by Arie de Jong included adding r just to make things even more complicated, rather than scrapping the existing complications). Suffices to say that Esperanto was a lot readily available as far as Europeans were concerned.
The word occasionally pops up in French band names and the like, and is Russian slang for writing Russian using Latin letters as if they were Cyrillic (similar to l337 speak). Also used in Esperanto for the same effect as "It's all greek to me!".
"I tried learning Volapük, but found speaking English backwards sounded cool enough" (Post-graduate lingustics student)
"I can write russian using BO/\RTTI-OK (ru: volyapyuk/воляпюк) encoding" (Russian l337 speaker)
"That French band Volapuk is pretty awesome eh?" (International music lover commenting on own tastes)
"Crazy volapükists, did they seriously think they could steal the final victory from us?" (Esperantist from the days when everyone in Europe had a revolution or three up their sleeves)