Original sentence: (pst) To defeat unexpectedly (an opponent favored to win).A disturbance, disorder, or state of agitation.A game or contest in which the favorite is defeated.A tool used for upsetting; a swage.All rights reserved.An upset part or piece.Exhibiting signs and symptoms of indigestion: an upset stomach.Having been overturned; capsized.In a state of emotional or mental distress; distraught: upset parents.Published by Houghton Mifflin Company.See Synonyms at overthrow.The American Heritage® Dictionary of the English Language, Fourth Edition copyright ©2000 by Houghton Mifflin Company.The act of upsetting or the condition of being upset.To become disturbed.To become overturned; capsize.To cause to turn or tip over; capsize.To distress or perturb mentally or emotionally: The bad news upset me.To disturb the functioning, order, or course of: Protesters upset the meeting by chanting and shouting.To make (a heated metal bolt, for example) shorter and thicker by hammering on the end.To overthrow; overturn: upset a will.Updated in 2009.[-setting, -set].[Middle English upsetten, to set up : up-, up- + setten, to set; see set1.a disturbance or disorder of the emotions, mind, or body.an unexpected defeat or reversal, as in a contest or plans.emotionally or physically disturbed or distressed.to disrupt the normal state or progress of: bad weather upset their plans.to disturb mentally or emotionally.to make physically ill: it still seems to upset my stomach.to turn or tip over.upset    Also found in: Acronyms, Idioms, Encyclopedia, Wikipedia, Hutchinson  0.37 sec.upsetting adj.up·set (p-st).up·set, up·set·ting, up·sets.up·setter n.up·setting·ly adv