Source : Webster's Revised Unabridged Dictionary (1913)

Upset \Up*set"\, v. t. (Basketwork)
   To turn upwards the outer ends of (stakes) so as to make a
   foundation for the side of a basket or the like; also, to
   form (the side) in this manner.

Upset \Up*set"\, v. t.
   1. To set up; to put upright. [Obs.] ``With sail on mast
      upset.'' --R. of Brunne.

   2.
      (a) To thicken and shorten, as a heated piece of iron, by
          hammering on the end.
      (b) To shorten (a tire) in the process of resetting,
          originally by cutting it and hammering on the ends.

   3. To overturn, overthrow, or overset; as, to upset a
      carriage; to upset an argument. ``Determined somehow to
      upset the situation.'' --Mrs. Humphry Ward.

   4. To disturb the self-possession of; to disorder the nerves
      of; to make ill; as, the fright upset her. [Colloq.]

Upset \Up*set"\, v. i.
   To become upset.

Upset \Up"set`\, a.
   Set up; fixed; determined; -- used chiefly or only in the
   phrase upset price; that is, the price fixed upon as the
   minimum for property offered in a public sale, or, in an
   auction, the price at which property is set up or started by
   the auctioneer, and the lowest price at which it will be
   sold.

         After a solemn pause, Mr. Glossin offered the upset
         price for the lands and barony of Ellangowan. --Sir W.
                                                  Scott.

Upset \Up"set`\, n.
   The act of upsetting, or the state of being upset; an
   overturn; as, the wagon had an upset.

Source : WordNet®

upset
     v 1: disturb the balance or stability of; "The hostile talks
          upset the peaceful relations between the two countries"
     2: cause to lose one's composure [syn: {discompose}, {untune},
        {disconcert}, {discomfit}]
     3: move deeply; "This book upset me"; "A troubling thought"
        [syn: {disturb}, {trouble}]
     4: cause to overturn from an upright or normal position; "The
        cat knocked over the flower vase"; "the clumsy customer
        turned over the vase"; "he tumped over his beer" [syn: {overturn},
         {tip over}, {turn over}, {knock over}, {bowl over}, {tump
        over}]
     5: form metals with a swage [syn: {swage}]
     6: defeat suddenly and unexpectedly; "The foreign team upset
        the local team"
     [also: {upsetting}]

upset
     adj 1: afflicted with or marked by anxious uneasiness or trouble or
            grief; "too upset to say anything"; "spent many
            disquieted moments"; "distressed about her son's
            leaving home"; "lapsed into disturbed sleep"; "worried
            parents"; "a worried frown"; "one last worried check
            of the sleeping children" [syn: {disquieted}, {distressed},
             {disturbed}, {worried}]
     2: thrown into a state of disarray or confusion; "troops
        fleeing in broken ranks"; "a confused mass of papers on
        the desk"; "the small disordered room"; "with everything
        so upset" [syn: {broken}, {confused}, {disordered}]
     3: used of an unexpected defeat of a team favored to win; "the
        Bills' upset victory over the Houston Oilers" [syn: {upset(a)}]
     4: mildly physically distressed; "an upset stomach"
     5: having been turned so that the bottom is no longer the
        bottom; "an overturned car"; "the upset pitcher of milk";
        "sat on an upturned bucket" [syn: {overturned}, {upturned}]
     n 1: an unhappy and worried mental state; "there was too much
          anger and disturbance"; "she didn't realize the upset
          she caused me" [syn: {disturbance}, {perturbation}]
     2: the act of disturbing the mind or body; "his carelessness
        could have caused an ecological upset"; "she was
        unprepared for this sudden overthrow of their normal way
        of living" [syn: {derangement}, {overthrow}]
     3: condition in which there is a disturbance of normal
        functioning; "the doctor prescribed some medicine for the
        disorder"; "everyone gets stomach upsets from time to
        time" [syn: {disorder}]
     4: a tool used to thicken or spread (the end of a bar or a
        rivet etc.) by forging or hammering or swaging [syn: {swage}]
     5: the act of upsetting something; "he was badly bruised by the
        upset of his sled at a high speed" [syn: {overturn}, {turnover}]
     6: an improbable and unexpected victory; "the biggest upset
        since David beat Goliath" [syn: {overturn}]
     [also: {upsetting}]