STOCHASTIC
Here’s a word I’ve been practically surrounded by here in the library for the last ten years, and never looked it up before. It is an excellent word.
According to OED:
1. Pertaining to conjecture. Now rare or Obs.
2. a. Randomly determined; that follows some random probability distribution or pattern, so that its behaviour may be analysed statistically but not predicted precisely; stochastic process = random process s.v. RANDOM a. 1b.
etc.
Style points to anyone who can find an everyday usage outside the context of math or computing.
Runner-up: coyoteo. Coyoteo is fun to say.