abstruse

On March 19, 2005, alone in his office with the door closed and the shades drawn, reading an abstruse textbook on credit derivatives, Michael Burry got an idea: credit default swaps on subprime mortgage bonds.

Also, his estimate arose from abstruse economic formulas and lots of magic asterisks.

That might sound like an abstruse philosophical argument, but he says it's a hot debate within the scientific community.

It’s not exactly secret, but it’s abstruse enough that they hope most people, who aren’t fully conversant with the complexities of the program, won’t get the drift.

I wasn’t expecting to write such a sentence about an abstract and some might even say abstruse Sondheim musical that has had only one short-lived Broadway revival.