- upset [up set′; ] for n. always, and for adj. also [, up′set΄]vt.upset, upsetting [ME upsetten: see UP1 & SET]1. Obs. to set up; erect2.a) to tip over; overturn [to upset a vase]b) to overthrow or defeat unexpectedly3.a) to disturb the functioning, fulfillment, or completion of [to upset a busy schedule]b) to disturb mentally or emotionally [upset by bad news]c) to disturb physically; make sick [to upset the stomach]4. Mech.a) to shorten and thicken (a red-hot iron) by beating on the endb) to shorten (a metal tire) in the process of resetting itvi.to become overturned or upsetn.1. an upsetting or being upset; specif.,a) a tipping over, knocking over, etc.b) an unexpected victory or defeatc) a disturbance or disorder, specif. of an emotional or physical nature2. Mech.a) a swage used for upsettingb) an upset piece or partadj.1. Rare set up; erected2.a) tipped over; overturnedb) disturbed or disorderedupsettern.SYN.- UPSET is the ordinary word implying a toppling, disorganization, etc. as a result of a loss of balance or stability [to upset a glass, one's plans, etc.; emotionally upset]; OVERTURN implies a turning of a thing upside down or flat on its side and, in extended use, connotes the destruction of something established [to overturn a chair, a government, etc. ]; CAPSIZE specifically implies the overturning or upsetting of a boat
English World dictionary. V. Neufeldt. 2014.