I should have kept track of such things earlier; I've heard some good ones over the years.
Today's euphemism, on UA#134 SFO-ORD, was a faulty "passive restraint" system in the cockpit.
The co-pilot's seatbest was broken. Why they couldn't have just said that, I don't know. Can't most people relate to the idea of a stuck seatbelt? Is UA more "creative" than other airlines?