upsett

Noun

upset (countable and uncountable, plural upsets)

1. (uncountable) Disturbance or disruption.
   • My late arrival caused the professor considerable upset.

   Synonyms:

   disruption, disturbance, distraction

2. (countable) An unexpected victory of a competitor or candidate that was not favored to win.
   • But it is probably the biggest upset for the away side since Ronnie Radford smashed a famous goal as Hereford defeated Newcastle 2-1 in 1972.2011 January 8, Paul Fletcher, “Stevenage 3 - 1 Newcastle”, in BBC
3. An overturn.
   • "collision and upset": impact with another object or an overturn for whatever reason.
4. An upset stomach.
   • “Bob, let's cancel the baby sitter. With this upset stomach, I can't go out tonight.”
     “Sure you can, Liz! Try Pepto-Bismol. Hospital tests prove it relieves upsets. And it's great for indigestion or nausea, too!”1958 May 12, Life, volume 44, number 19, advertisements, page 110
5. An upper set; a subset (X,≤) of a partially ordered set with the property that, if x is in U and x≤y, then y is in U.
6. The dangerous situation where the flight attitude or airspeed of an aircraft is outside the designed bounds of operation, possibly resulting in loss of control.
   • The Board determines that the probable cause of this accident was the unfavorable interaction of severe vertical air drafts and large longitudinal control displacements resulting in a longitudinal upset from which a successful recovery was not made.1965 June 1, Civil Aeronautics Board, “Synopsis”, in Aircraft Accident Report: Northwest Airlines, Inc., Boeing 720B, N724US, Near Miami, Florida, February 12, 1963, retrieved 25 Nov 2022, page 1

See all 18 meanings of upset