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tr.v. up·set, up·set·ting, up·sets
1. To cause to overturn; knock or tip over: upset the flowerpot.
a. To disturb the functioning, order, or course of: Protesters upset the meeting by chanting and shouting. See Synonyms at overthrow.
b. To cause (the stomach) to feel ill.
3. To distress or perturb mentally or emotionally: The bad news upset me.
4. (ŭp′sĕt′) To defeat unexpectedly (an opponent favored to win).
5. To make (a heated metal bolt, for example) shorter and thicker by hammering on the end.
1. The act of upsetting or the condition of being upset: the upset of the vase.
a. A disturbance, disorder, or state of agitation: an upset of my routine.
b. A condition of indigestion: a remedy for stomach upset.
3. A game, contest, or election in which the favorite is defeated.
a. A tool used for upsetting; a swage.
b. An upset part or piece.
1. Having been overturned: an upset vase.
2. Exhibiting signs and symptoms of indigestion: an upset stomach.
3. In a state of emotional or mental distress; distraught: upset parents.
[Middle English upsetten, to set up : up-, up- + setten, to set; see set1.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.