The Collaborative International Dictionary of English v.0.48:

Usury \U"su*ry\, n. [OE. usurie, usure, F. usure, L. usura use,
   usury, interest, fr. uti, p. p. usus, to use. See Use, v.
   t.]
   [1913 Webster]
   1. A premium or increase paid, or stipulated to be paid, for
      a loan, as of money; interest. [Obs. or Archaic]
      [1913 Webster]

            Thou shalt not lend upon usury to thy brother; usury
            of money, usury of victuals, usury of anything that
            is lent upon usury.                   --Deut. xxiii.
                                                  19.
      [1913 Webster]

            Thou oughtest therefore to have put my money to the
            exchanges, and then at my coming I should have
            received mine own with usury.         --Matt. xxv.
                                                  27.
      [1913 Webster]

            What he borrows from the ancients, he repays with
            usury of ??is own.                    --Dryden.
      [1913 Webster]

   2. The practice of taking interest. [Obs.]
      [1913 Webster]

            Usury . . . bringeth the treasure of a realm or
            state into a few ??nds.               --Bacon.
      [1913 Webster]

   3. (Law) Interest in excess of a legal rate charged to a
      borrower for the use of money.
      [1913 Webster]

   Note: The practice of requiring in repayment of money lent
         anything more than the amount lent, was formerly
         thought to be a great moral wrong, and the greater, the
         more was taken. Now it is not deemed more wrong to take
         pay for the use of money than for the use of a house,
         or a horse, or any other property. But the lingering
         influence of the former opinion, together with the fact
         that the nature of money makes it easier for the lender
         to oppress the borrower, has caused nearly all
         Christian nations to fix by law the rate of
         compensation for the use of money. Of late years,
         however, the opinion that money should be borrowed and
         repaid, or bought and sold, upon whatever terms the
         parties should agree to, like any other property, has
         gained ground everywhere. --Am. Cyc.
         [1913 Webster]

WordNet (r) 3.0 (2006):

usury
    n 1: an exorbitant or unlawful rate of interest [syn: usury,
         vigorish]
    2: the act of lending money at an exorbitant rate of interest

Moby Thesaurus II by Grady Ward, 1.0:

56 Moby Thesaurus words for "usury":
   Cosa Nostra, Mafia, advance, advancement, advancing, bank rate,
   black market, bootlegging, compensatory interest,
   compound interest, discount rate, exorbitant interest,
   exploitation, extortion, gambling, gray market, gross interest,
   highway robbery, holdup, illegal commerce, illegal operations,
   illegitimate business, illicit business, interest, interest rate,
   lend-lease, lending, lending at interest, loan-sharking, loaning,
   lucrative interest, moneylending, moonshining, mortgage points,
   narcotics traffic, net interest, organized crime, overassessment,
   overcharge, penal interest, premium, price, price of money,
   prostitution, protection racket, racket, rate, rate of interest,
   shady dealings, shylocking, simple interest, surcharge,
   the rackets, the syndicate, traffic in women, white slavery



Easton's 1897 Bible Dictionary:

Usury
   the sum paid for the use of money, hence interest; not, as in
   the modern sense, exorbitant interest. The Jews were forbidden
   to exact usury (Lev. 25:36, 37), only, however, in their
   dealings with each other (Deut. 23:19, 20). The violation of
   this law was viewed as a great crime (Ps. 15:5; Prov. 28:8; Jer.
   15:10). After the Return, and later, this law was much neglected
   (Neh. 5:7, 10).


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

USURY, contracts. The illegal profit which is required and received by the
lender of a sum of money from the borrower for its use. In a more extended
and improper sense, it is the receipt of any profit whatever for the use of
money: it is only in the first of these senses that usury will be here
considered.
     2. To constitute a usurious contract the following are the requisites:
1. A loan express or implied. 2. An agreement that the money lent shall be
returned at all events. 3. Not only that the money lent shall be returned,
but that for such loan a greater interest than that fixed by law shall be
paid.
     3.-1. There must be a loan in contemplation of the parties; 7 Pet. S.
C. Rep. 109, 1 Clarke R. 252; and if there be a loan, however disguised, the
contract will be usurious, if it be so in other respects. Where a loan was
made of depreciated bank notes to be repaid in sound funds, to enable the
borrower to pay a debt he owed dollar for dollar, it was considered as not
being usurious. 1 Meigs, R. 585. The bona fide sale of a note, bond or other
security at a greater discount than would amount to legal interest, is not
per se, a loan, although the note may be endorsed by the seller, and he
remains responsible. 9 Pet. S. C. Rep. 103; 1 Clarke, R. 30. But, if a note,
bond; or other security be made with a view to evade the laws of usury, and
afterwards sold for a less amount than the interest, the transaction will be
considered a loan; 2 Johns. Cas. 60; 3 Johns. Cas. 66; 15 Johns. R. 44 2
Dall. 92; 12 Serg. & Rawle, 46 and a sale of a man's own note, endorsed by
himself, will, be considered a loan. lt is a general rule that a contract,
which, in its inception, is unaffected by usury, can never be invalidated by
any subsequent usurious transaction. 7 Pet. S. C. Rep. 109. On the contrary,
when the contract was originally usurious, and there is a substitution by a
new contract, the latter will generally be considered usurious. 15 Mass. R.
96.
     4.-2. There must be a contract for the return of the money at all
events; for if the return of the principal with interest, or of the
principal only, depend upon a contingency, there can be no usury; but if the
contingency extend only to interest, and the principal be beyond the reach
of hazard, the lender will be guilty of usury, if he received interest
beyond the amount allowed by law. As the principal is put to hazard in
insurances, annuities and bottomry, the parties may charge and receive
greater interest than is allowed by law in common cases, and the transaction
will not be usurious.
     5.-3. To constitute usury the borrower must not only be obliged to
return the principal at all events, but more than lawful interest: this part
of the agreement must be made with full consent and knowledge of the
contracting parties. 3 Bos. & Pull, 154. When the contract is made in a
foreign country the rate of interest allowed by the laws of that country may
be charged, and it will not be usurious, although greater than the amount
fixed by law in this. Story, Confl. of Laws, Sec. 292. Vide, generally, Com.
Dig. h.t.; Bac. Ab. h.t.; 8 Com. Dig. h.t.; Lilly's Reg. h.t.; Dane's Ab.
h.t.; Petersdorff's Ab. h.t.; Vin. Ab. h.t.; 2 Bl. Com. 454; Comyn on Usury,
passim; 1 Pt. S. C Rep. Index, h.t.; 1 Supp. to Yes. jr. 307, 337; Yelv. 47;
1 Ves. jr. 527; 1 Saund 295, note 1; Poth. h.t.; and the article Anatocism;
Interest.