The Collaborative International Dictionary of English v.0.48:

Payment \Pay"ment\, n. [F. payment, paiement. See Pay to
   requite.]
   1. The act of paying, or giving compensation; the discharge
      of a debt or an obligation.
      [1913 Webster]

            No man envieth the payment of a debt. --Bacon.
      [1913 Webster]

   2. That which is paid; the thing given in discharge of a
      debt, or an obligation, or in fulfillment of a promise;
      reward; recompense; requital; return. --Shak.
      [1913 Webster]

   3. Punishment; chastisement. [R.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

payment
    n 1: a sum of money paid or a claim discharged [ant: default,
         nonpayment, nonremittal]
    2: the act of paying money [syn: payment, defrayal,
       defrayment] [ant: evasion, nonpayment]
    3: an act of requiting; returning in kind [syn: requital,
       payment]

Moby Thesaurus II by Grady Ward, 1.0:

101 Moby Thesaurus words for "payment":
   bait, base pay, bribe, budgeting, carrot, castigation, charge,
   chastening, chastisement, compensation, condign punishment,
   contribution, correction, costing, costing-out, debit, debiting,
   deficit spending, deserts, disbursal, disbursement,
   disciplinary measures, discipline, dismissal wage, distribution,
   earnings, encouragement, escalator clause, escalator plan,
   expenditure, expense, fee, ferule, fillip, financial remuneration,
   gross income, guaranteed annual wage, hire, incentive, incitement,
   income, inducement, infliction, interest, invitation, judgment,
   judicial punishment, living wage, lure, minimum wage, nemesis,
   net income, outlay, pains, pains and punishments, pay,
   pay and allowances, payroll, penal retribution, penalty, penology,
   percentage, persuasive, portal-to-portal pay, profit, provocation,
   punishment, punition, purchasing power, real wages, remuneration,
   retribution, retributive justice, reward, salary, scheduling,
   scourge, severance pay, sliding scale, spending, stimulation,
   stimulative, stimulus, sweetener, sweetening, take-home,
   take-home pay, taxable income, total compensation, wage,
   wage control, wage freeze, wage reduction, wage rollback,
   wage scale, wages, wages after deductions, wages after taxes,
   well-deserved punishment, what-for, whet



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

PAYMENT, contracts. That which is given to execute what has been promised;
or it is the fulfillment of a promise. Solvere dicimus cum quis fecit, quod
facere promisit.  But though this is the general acceptation of the word,
yet by payment is understood, every way by which the creditor is satisfied
or ought to be, and the debtor, liberated for example, an accord and
satisfaction will operate as a payment. If I owe you a sum of money, for the
security of which I give you a mortgage, and afterwards you consent to
receive in payment a tract of land, from the moment the sale is complete,
the first obligation, with all its accessories, is extinct, although you
should be afterwards evicted of the property sold. 7 Toull. n. 46 2  Mart.
Lo. Rep. N. S. 144; S. C. 2 Harr. Cond. Lo. R. 621, 624.
     2. This subject will be considered by taking a separate view of the
person by whom the payment may be made; to whom it may be made; when and
where it ought to be made; how it ought to be made; the effect of the
payment.
     3.-1. The payment may be made by the real debtor and other persons
from whom the creditor has a right to demand it; an agent may make payment
for his principal; and any mode of payment by the agent, accepted and
received as such by the creditor, as an absolete payment will have the
effect to discharge the principal, whether known or unknown, and whether it
be in the usual course of business or not. If, for example, a factor or
other agent should be employed to purchase goods for his principal, or
should be entrusted, with money to be paid for him, and, instead of
receiving the money, the creditor or seller should take the note of the
factor or agent; payable at a future day, as an absolute payment, the
principal would be discharged from the debt. 3 Chit. Com. Law, 204; 1 B. &
Ald. 14; 6 B. & C. 160; 7 B. & C. 17. When such note has been, received
conditionally and not as an absolute payment, it would not have the effect
of a payment by the principal; and whether so received or not is a fact to
be decided by the jury. 1 Cowen, R, 259, 383; 9 John. R:, 310; 6 Cowen, R.
181; 7 John. R. 311; 15 John. R. 276; 3 Wend. R. 83; 6 Wend. R. 475; 10
Wend. R. 271; 5 John., R. 68; 1 Liverm. Ag. 207.
     4. Payment may also be made by a third person a stranger to the
contract.
     5. In the payment of mortgages, it is a20rule, that the personal estate
shall be applied to discharge them when made by the testator or intestate
himself, to secure the payment of a debt due by him, because the personal
estate was benefited by the money borrowed; and it makes no difference
whether the mortgaged lands have been devised, or come to the heir by
descent. 2 Cruise, 1 Dig. 147. The testator may, however, exempt the
personal estate from the payment, and substitute the real in its place. But
when the mortgage was not given by the deceased, but be acquired the real
estate subject to it, it never was his debt, and therefore his personal
estate is not bound to pay the mortgage debt, but it must be paid by the
real estate. 2 Cruise, Dig. 164-8; 3 John. Chan. R. 252; 2 P. Wms. 664, n.
1; 2 Bro. C. C. 57; 2 Bro. C. C. 101, 152; 5 Ves. jr. R. 534; 14 Ves. 417.
     6.-2. It must be made by the creditor himself, or his assigns, if
known, or some person authorized by him, either expressly or by implication;
as to his factor; Cowp. 251: to his broker, 1 Maul. & Selw. 576; 4 Id. 566;
4 Taunt. 242; 1 Stark. Ca. 238.
     7. In the case of partners and other joint creditors, or joint
executors or administrators, payment to one is generally a valid payment.
When an infant is a creditor, payment must be made to his guardian. A
payment may be good when made to a person who had no authority to receive
it, if the creditor shall afterwards ratify it. Poth. Obl. n. 528.
     8.-3. Time and place of payment: first, as to the time. When the
contract is, that payment shall be made at a future time, it is clear that
nothing can be demanded until after it has elapsed, or until any other
condition to which the payment is subject, has been fulfilled; and in a case
where the goods had been sold at six or nine months, the debtor had the
option as to those two terms. 5 Taunt, 338. When no time of payment is
mentioned in the agreement, the money is payable immediately. 1 Pet. 455; 4
Rand. 346.
     9. Secondly, the payment must be made at the place agreed upon in the
contract; but in the absence of such agreement, it must be made agreeably to
the presumed intention of the parties, which, among other things, may be
ascertained by the nature of the thing to be paid or delivered, or by the
custom in such cases.
    10.-4. How the payment ought to be made. To make a valid payment, so
as to compel the receiver to take it, the whole amount due must be paid;
Poth. Obl. n. 499, or n. 534, French edition; when a part is accepted, it is
a payment pro tanto. The payment must be made in the thing agreed upon; but
when it ought to be made in money, it must be made in the lawful coin of the
country, or in bank notes which are of the value they are represented to be.
A payment made in bills of an insolvent bank, though both parties may be
ignorant of its insolvency, it has been held, did not discharge the debt; 11
Vern. 676; 6 Hill, 340; but see 1 W. & S. 92; 8 Yerg. 175; and a payment in
counterfeit bank notes is a nullity. 2 Hawks, 326; 3 Hawks, 568, 6 Hill,
840. In general, the payment of a part of a debt, after it becomes due, will
not discharge the whole, although there may be an agreement by the debtor
that it should have that effect, because there is no consideration for such
agreement. But see 3 Kelly's R. 210, contra. A payment of a part, before it
is due, will discharge the whole, when so agreed.
    11.-5. The payment, when properly made, discharges the debtor from his
obligation. Sometimes a payment extinguishes several obligations; this
happens when the thing given to discharge an obligation was the same which
is the object of another obligation. Poth. Obl. 552.
    12. A single payment may discharge several debts; as, for example if
Peter be indebted to Paul one thousand dollars, and Paul being indebted to
James, Paul give an order to Peter to pay Tames this money; the payment made
by Peter to James discharges both the obligations due by Peter to Paul, and
by Paul to James. Poth. Ob. n. 553. This rule, that a payment made in order
to acquit or discharge an obligation, extinguishes the other obligations
which have the same object, takes place also when there are several debtors
as regards the whole of them. If, for example, Peter trust Paul on the
credit of James, a payment by Paul discharges both himself and James. Poth.
Obl. n. 554.
    13. But in case money or other things have been delivered to a person
who was supposed to be entitles to them as a creditor, when he was not, this
is not a payment, and the whole, if nothing was due, or if the debt was less
than the amount paid, the surplus, may be recovered in action for money bad
and received. Vide, generally, Bouv. Inst. Index, h.t.; Com. Dig. 473; 8
Com. Dig. 607; 16 Vin 6; 1 Vern. by Raith. 3, 150 n. Yelv. 11 a; 1 Salk. 22;
15 East, 12; 8 East, R. 111; 2 Ves. jr. 11; Phil. Ev. Index, b, t,; Stark.
Ev. h.t.; Louis. Code, art. 2129; Ayl. Pand. 565; 1 Sell. Pr. 277; Dane's
Ab. Index, h.t.; Toull. lib. 3, tit. 3, c. 5; Pardes. part 2, tit. 2, c. 1
Merl. Repert. h.t.; Chit. Contr. Index, h.t.; 3 Eng. C. L. Rep. 130. As to
what transfer will amount to an assignment or a payment and extinguishment
of a claim, see 6 John. Ch. R. 395; Id. 425; 2 Ves. jr. 261 18 Ves. jr. 384;
1 N. H. Rep. 167; 1 N. H. Rep. 252; 2 N. H. Rep. 300; 3 John. Ch. R. 53.



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

PAYMENT, pleadings. The name of a plea by which the defendant alleges that
he has paid the debt claimed in the declaration; this plea must conclude to
the country. 4 Call, 371; Minor, 137. Vide Solvit ad them; Solvit post diem.