I did this once with a multi-chapter Buffy/Star Trek crossover that had a single-word title,
Omphalos, which (if you looked it up and realise which context I was using) gave away major plot points - and didn't explain it for several chapters. I don't think anyone looked it up...
If you don't want to read the story,
the Omphalos hypothesis was a 19th century idea that the universe was created recently but deliberately made to look old, e.g. by creating fossils and other evidence of a history millions of years old. It's inherently unproveable. In the story "recently" turns out to be at the moment the story begins, with some interesting consequences in a setting that has faster than light travel...
