The Collaborative International Dictionary of English v.0.48:

Surcharge \Sur*charge"\, n. [F.]
   1. An overcharge; an excessive load or burden; a load greater
      than can well be borne.
      [1913 Webster]

            A numerous nobility causeth poverty and
            inconvenience in a state, for it is surcharge of
            expense.                              --Bacon.
      [1913 Webster]

   2. (Law)
      (a) The putting, by a commoner, of more beasts on the
          common than he has a right to.
      (b) (Equity) The showing an omission, as in an account,
          for which credit ought to have been given. --Burrill.
          [1913 Webster]

   3. (Railroads) A charge over the usual or legal rates.
      [Webster 1913 Suppl.]

   4. Something printed or written on a postage stamp to give it
      a new legal effect, as a new valuation, a place, a date,
      etc.; also (Colloq.), a stamp with a surcharge.
      [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Surcharge \Sur*charge"\, v. t. [imp. & p. p. Surcharged; p.
   pr. & vb. n. Surcharging.] [F. surcharger. See Sur-, and
   Charge, and cf. Overcharge, Supercharge, Supercargo.]
   1. To overload; to overburden; to overmatch; to overcharge;
      as, to surcharge a beast or a ship; to surcharge a cannon.
      [1913 Webster]

            Four charged two, and two surcharged one. --Spenser.
      [1913 Webster]

            Your head reclined, as hiding grief from view,
            Droops like a rose surcharged with morning dew.
                                                  --Dryden.
      [1913 Webster]

   2. (Law)
      (a) To overstock; especially, to put more cattle into, as
          a common, than the person has a right to do, or more
          than the herbage will sustain. Blackstone.
      (b) (Equity) To show an omission in (an account) for which
          credit ought to have been given. --Story. Daniel.
          [1913 Webster]

   3. To print or write a surcharge on (a postage stamp).
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

surcharge
    n 1: an additional charge (as for items previously omitted or as
         a penalty for failure to exercise common caution or common
         skill)
    v 1: charge an extra fee, as for a special service
    2: rip off; ask an unreasonable price [syn: overcharge,
       soak, surcharge, gazump, fleece, plume, pluck,
       rob, hook] [ant: undercharge]
    3: fill to capacity with people; "The air raids had surcharged
       the emergency wards"
    4: print a new denomination on a stamp or a banknote
    5: fill to an excessive degree; "The air was surcharged with
       tension"
    6: place too much a load on; "don't overload the car" [syn:
       overload, surcharge, overcharge]
    7: show an omission in (an account) for which credit ought to
       have been given

Moby Thesaurus II by Grady Ward, 1.0:

93 Moby Thesaurus words for "surcharge":
   bale, bleed, bleed white, burden, burdening, burthen, cargo,
   charge, charging, choke, clip, congest, congestion, cram, crowd,
   cumber, cumbrance, deadweight, doctor accounts, drag, drench,
   encumbrance, engorgement, exploit, exploitation, extortion, fleece,
   freight, garble accounts, glut, gluttonize, gorge, gouge, handicap,
   highway robbery, hold up, holdup, hyperemia, incubus, incumbency,
   jam, jam-pack, lading, load, loading, loan-sharking, millstone,
   oppression, overassessment, overbrimming, overburden, overcharge,
   overfeed, overfill, overflow, overfreight, overfullness, overlade,
   overload, overprice, overspill, overstuff, overtax, overtaxing,
   overweight, overweighting, pack, plethora, pressure, profiteer,
   repletion, saddling, salt, satiate, satiety, saturate, saturation,
   screw, shylocking, skin, soak, stick, sting, stuff, supercharge,
   superincumbency, supersaturate, supersaturation, surfeit, swindle,
   taxing, usury, victimize



Bouvier's Law Dictionary, Revised 6th Ed (1856):

SURCHARGE, chancery practice. When a bill is filed to open an account,
stated, liberty is sometimes given to the plaintiff to surcharge and falsify
such account. That is, to examine not only errors of fact, but errors of
law. 2 Atk. 112; 11 Wheat. 237; 2 Ves. 565.
     2. "These terms, `surcharge,' and `falsify,'" says Mr. Justice Story, 1
Eq. Jur. Sec. 525, "have a distinct sense in the vocabulary of courts of
equity, a little removed from that, which they bear in the ordinary language
of common life. In the language of common life, we understand `surcharge' to
import an overcharge in quantity, or price, or degree, beyond what is just
and reasonable. In this sense, it is nearly equivalent to `falsify;' for
every item, which is not truly charged, as it should be, is false; and by
establishing such overcharge it is falsified. But, in the sense of courts of
equity, these words are used in contradistinction to each other. A surcharge
is appropriately applied to the balance of the whole account; and supposes
credits to be omitted, which ought to be allowed. A falsification applies to
some item in the debets; and supposes, that the item is wholly false, or in
some part erroneous. This distinction is taken notice of by Lord Hardwicke;
and the words used by him are so clear, that they supersede all necessity
for farther commentary. `Upon a liberty to the plaintiff to surcharge, and
falsify,' says he, `the onus probandi is always on the party having that
liberty; for the court takes it as a stated account, and establishes it.
But, if any of the parties can show an omission, for which credit ought to
be, that is, a surcharge, or if anything is inserted, that is a wrong
charge, he is at liberty to show it, and that is a falsification. But that
must be by proof on his side. And that makes a great difference between the
general cases of an open account, and were only [leave] to surcharge and
falsify; for such must be made out."