Etymology From Middle English upset (“the act of setting up; establishment”), from Middle English upsetten, corresponding to up- + set. Cognate with Middle Low German upset (“setup; arrangement”).
1
Of a person Angry, distressed, or unhappy
He was upset when she refused his friendship.
My children often get upset with their classmates.
1 more example
We were shocked when we asked a disruptive man in the front row to move to the back, and when he subsequently left, the producer's helpers were so upset for him they gave him two free tickets to the next 'women's music' production.1981 December 5, Jana Runnals, Rosemary Schonfeld, “The Liberalisation of 'Women's Music'”, in Gay Community News, volume 9, number 20, page 9:
Etymology From Middle English upset (“the act of setting up; establishment”), from Middle English upsetten, corresponding to up- + set. Cognate with Middle Low German upset (“setup; arrangement”).
My late arrival caused the professor considerable upset.
2
Government, Hobbies, Lifestyle, Politics, Sports 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:
Sanders’s win in Michigan was one of the greatest upsets in modern political history.2016 March 9, Harry Enten, “What The Stunning Bernie Sanders Win In Michigan Means”, in FiveThirtyEight:
1 more example
The sudden rise of Shah’s party is a stunning upset for the small Himalayan country of 30 million wedged between India and China.2026 March 11, Chad de Guzman, “Who Is Balendra Shah, the Rapper On Track to Become Nepal’s Next Prime Minister”, in TIME, archived from the original on 11 Mar 2026:
"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
Mathematics, Sciences 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
Aeronautics, Aerospace, Aviation, Business, Engineering, Natural sciences, Physical sciences 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:
7
A woven row supporting the foundation rods for the uprights of a basket.
Willow basket making, an artisan inserting bye-stakes in the upsets.1972, Nilima Roy, Basketry and Mat-weaving in India:
Etymology From Middle English upset (“the act of setting up; establishment”), from Middle English upsetten, corresponding to up- + set. Cognate with Middle Low German upset (“setup; arrangement”).
I’m sure the bad news will upset him, but he needs to know.
2
To disturb, disrupt or adversely alter (something).
Introducing a foreign species can upset the ecological balance.
The fatty meat upset his stomach.
3
To tip or overturn (something).
1924, W. D. Ross translator, Aristitle, Metaphysics, Book 1, Part 9, The Classical Library, Nashotah, Wisconsin, 2001. But this argument, which first Anaxagoras and later Eudoxus and certain others used, is very easily upset; for it is not difficult to collect many insuperable objections to such a view.
4
To defeat unexpectedly.
Truman upset Dewey in the 1948 US presidential election.
5
To be upset or knocked over.
The carriage upset when the horse bolted.
[T]he locomotive exploded and upset, and was completely wrecked.1880 January 1, The Locomotive, volume 1, number 1, Hartford, Conn.: The Hartford Steam Boiler Inspection And Insurance Company, page 9:
Arts, Crafts, Engineering, Hobbies, Lifestyle, Metallurgy, Metalworking, Natural sciences, Physical sciences To thicken and shorten a soft or heated piece of metal, by forging or hammering on the end, to shape, for example, rivets or internal combustion engine valves.
8
To shorten (a tire) in the process of resetting, originally by cutting it and hammering on the ends.
9
To support with an upset (type of woven row).
Very coarse work is sided up without an upsett, or is upsetted with a pair instead of a wale.2012, Thomas Okey, An Introduction to the Art of Basket-Making, page 32: