The Collaborative International Dictionary of English v.0.48:

Pledge \Pledge\, n. [OF. plege, pleige, pledge, guaranty, LL.
   plegium, plivium; akin to OF. plevir to bail, guaranty,
   perhaps fr. L. praebere to proffer, offer (sc. fidem a trust,
   a promise of security), but cf. also E. play. [root]28. Cf.
   Prebend, Replevin.]
   1. (Law) The transfer of possession of personal property from
      a debtor to a creditor as security for a debt or
      engagement; also, the contract created between the debtor
      and creditor by a thing being so delivered or deposited,
      forming a species of bailment; also, that which is so
      delivered or deposited; something put in pawn.
      [1913 Webster]

   Note: Pledge is ordinarily confined to personal property; the
         title or ownership does not pass by it; possession is
         essential to it. In all these points it differs from a
         mortgage [see Mortgage]; and in the last, from the
         hypotheca of the Roman law. See Hypotheca. --Story.
         Kent.
         [1913 Webster]

   2. (Old Eng. Law) A person who undertook, or became
      responsible, for another; a bail; a surety; a hostage. "I
      am Grumio's pledge." --Shak.
      [1913 Webster]

   3. A hypothecation without transfer of possession.
      [1913 Webster]

   4. Anything given or considered as a security for the
      performance of an act; a guarantee; as, mutual interest is
      the best pledge for the performance of treaties. "That
      voice, their liveliest pledge of hope." --Milton.
      [1913 Webster]

   5. A promise or agreement by which one binds one's self to
      do, or to refrain from doing, something; especially, a
      solemn promise in writing to refrain from using
      intoxicating liquors or the like; as, to sign the pledge;
      the mayor had made no pledges.
      [1913 Webster]
      [1913 Webster]

   6. A sentiment to which assent is given by drinking one's
      health; a toast; a health.
      [1913 Webster]

   Dead pledge. [A translation of LL. mortuum vadium.] (Law)
      A mortgage. See Mortgage.

   Living pledge. [A translation of LL. vivum vadium.] (Law)
      The conveyance of an estate to another for money borrowed,
      to be held by him until the debt is paid out of the rents
      and profits.

   To hold in pledge, to keep as security.

   To put in pledge, to pawn; to give as security.
      [1913 Webster]

   Syn: See Earnest.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Pledge \Pledge\, v. t. [imp. & p. p. Pledged; p. pr. & vb. n.
   Pledging.] [Cf. OF. pleiger to give security. See Pledge,
   n.]
   1. To deposit, as a chattel, in pledge or pawn; to leave in
      possession of another as security; as, to pledge one's
      watch.
      [1913 Webster]

   2. To give or pass as a security; to guarantee; to engage; to
      plight; as, to pledge one's word and honor.
      [1913 Webster]

            We mutually pledge to each other our lives, our
            fortunes, and our sacred honor.       --The
                                                  Declaration of
                                                  Independence.
      [1913 Webster]

   3. To secure performance of, as by a pledge. [Obs.]
      [1913 Webster]

            To pledge my vow, I give my hand.     --Shak.
      [1913 Webster]

   4. To bind or engage by promise or declaration; to engage
      solemnly; as, to pledge one's self.
      [1913 Webster]

   5. To invite another to drink, by drinking of the cup first,
      and then handing it to him, as a pledge of good will;
      hence, to drink the health of; to toast.
      [1913 Webster]

            Pledge me, my friend, and drink till thou be'st
            wise.                                 --Cowley.
      [1913 Webster]

WordNet (r) 3.0 (2006):

pledge
    n 1: a deposit of personal property as security for a debt; "his
         saxophone was in pledge"
    2: someone accepted for membership but not yet fully admitted to
       the group
    3: a drink in honor of or to the health of a person or event
       [syn: pledge, toast]
    4: a binding commitment to do or give or refrain from something;
       "an assurance of help when needed"; "signed a pledge never to
       reveal the secret" [syn: assurance, pledge]
    v 1: promise solemnly and formally; "I pledge that I will honor
         my wife" [syn: pledge, plight]
    2: pay (an amount of money) as a contribution to a charity or
       service, especially at regular intervals; "I pledged $10 a
       month to my favorite radio station" [syn: pledge,
       subscribe]
    3: propose a toast to; "Let us toast the birthday girl!"; "Let's
       drink to the New Year" [syn: toast, drink, pledge,
       salute, wassail]
    4: give as a guarantee; "I pledge my honor"
    5: bind or secure by a pledge; "I was pledged to silence"

Moby Thesaurus II by Grady Ward, 1.0:

187 Moby Thesaurus words for "pledge":
   Bible oath, Greek, accounts payable, accounts receivable,
   affiliate, agree, amount due, associate, assurance, assure, avouch,
   avouchment, avow, bad debts, bail, belonger, bib, bill, bills,
   bind, bond, booze, borrowing, bottomry, brother, card-carrier,
   card-carrying member, cardholder, charges, charter member, cheer,
   chip in, chits, clubber, clubman, clubwoman, collateral, commit,
   committeeman, comrade, confide, consign, contract, contribute,
   contribute to, conventioneer, conventioner, conventionist,
   countersign, covenant, debt, deposit, dip, donate to,
   drain the cup, drink, drink in, drink off, drink to, drink up, due,
   dues, dues-paying member, earnest, earnest money, engage, enlistee,
   enrollee, entrust, escrow, extrajudicial oath, faith, fellow,
   financial commitment, floating debt, fraternity man, funded debt,
   gage, gift, gift with, give to, go bail, guarantee, guaranty,
   guildsman, guzzle, handsel, health, hock, honorary member, hostage,
   hypothecate, imbibe, impignorate, indebtedness, indebtment,
   initiate, insider, ironclad oath, joiner, judicial oath, kick in,
   liability, life member, loyalty oath, mainprise, make a promise,
   make imperative, make incumbent, maturity, member, mortgage,
   national debt, oath, oath of allegiance, oath of office, obligate,
   obligation, oblige, official oath, one of us, outstanding debt,
   parole, pass, pawn, pignus, plight, pop, post, promise,
   public debt, pull, put in hock, put in pawn, put up, quaff,
   recognizance, replevin, replevy, require, saddle with, score,
   security, sip, sister, socius, solemn declaration, solemn oath,
   sorority girl, sorority woman, spout, stake, subscribe, suck,
   suck in, suckle, sup, surety, swear, sweeten the kitty, swig,
   swill, test oath, tie, tipple, toast, token, token payment,
   toss down, toss off, tribute, troth, uncollectibles, undertake,
   undertaking, underwrite, unfulfilled pledge, vadimonium, vadium,
   vouch, vouchsafe, vow, warrant, warranty, wash down, word,
   word of honor



Easton's 1897 Bible Dictionary:

Pledge
   See LOAN.


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

PLEDGE or PAWN, contracts. These words seem indifferently used to convey the
same idea. Story on Bailm. Sec. 286.
     2. In the civil code of Louisiana, however, they appear not to have
exactly the same meaning. It is there said that pledges are of two kinds,
namely, the pawn, and the antichresis. Louis'. Code, art. 3101.
     3. Sir William Jones defines a pledge to be a bailment of goods by a
debtor to his creditor, to be kept till the debt is discharged. Jones'
Bailm. 117; Id. 36. Chancellor Kent, 2 Kent's Com. 449, follows the same
definition, and see 1 Dane's Abr. c. 17, art. 4. Pothier, De Nantissement,
art. prelim. 1, defines it to be a contract by which a debtor gives to his
creditor a thing to detain as security for his debt. The code Napoleon has
adopted this definition, Code Civ. art. 2071, and the Civil Code of
Louisiana has followed it. Louis. Code, 3100. Lord Holt's definition is,
when goods or chattels are delivered to another as a pawn, to be security
for money borrowed of him by the bailor and this, he adds, is called in
Latin vadium, and in English, a pawn or pledge. Ld. Raym. 909, 913.
     4. The foregoing definitions are sufficiently descriptive of the nature
of a pawn or pledge but they are in terms limited to cues where a thing is
given as a security for a debt; but a pawn may well be made as security for
any other engagement. 2 Bulst. 306; Pothier, De Nantissement, n. 11. The
definition of Domat is, therefore, more accurate, because it is more
comprehensive, namely, that it is an appropriation of the thing given for
the security of an engagement. Domat, B. 3, tit. 1, Sec. 1, n. 1. And,
according to Judge Story, it may be defined to be a bailment of personal
property, as security for some debt or engagement. Story on Bailm. Sec. 286.
     5. The term pledge or pawn is confined to personal property; and where
real or personal property is transferred by a conveyance of the title, as a
security, it is commonly denominated a mortgage.
     6. A mortgage of goods is, in the common law, distinguishable from a
mere pawn. By a grant or a conveyance of goods in gage or mortgage, the
whole legal title passes conditionally to the mortgagee; and if not redeemed
at the time stipulated, the title becomes absolute at law, though equity
will interfere to compel a redemption. But in a pledge a special property
only passes to the pledges, the general property remaining in the pledger. 1
Atk. 167; 6 East, 25; 2 Caines' C. Err. 200; 1 Pick. 889; 1 Pet. S. C. B.
449 2 Pick. R. 610; 5 Pick. R. 60; 8. Pick. R. 236; 9 Greenl. R. 82; 2 N. H.
Rep. 13; 5 N. H. Rep. 545; 5 John. R. 258; 8 John. R. 97; 10 John. R. 471; 2
Hall, R. 63; 6 Mass. R. 425; 15 Mass. R. 480. A mortgage may be without
possession, but a pledge cannot be without possession. 5 Pick. 59, 60; and
see 2 Pick. 607.
     7. Things which are the subject of pledge or pawn are ordinarily goods
and chattels; but money, negotiable instruments, choses in action, and
indeed any other valuable thing of a personal nature, such as patent-rights
and manuscripts, may, by the common law, be delivered in pledge. 10 Johns.
R. 471, 475; 12 Johns. R. 146; 10 Johns. R. 389; 2 Blackf. R. 198; 7 Greenl.
R. 28; 2 Taunt. R. 268; 13 Mass. 105; 15 Mass. 389; Id. 534; 2 Caines' C.
Err. 200; 1 Dane's Abr. ch. 17, art. 4, Sec.  ii. See Louis. Code, art.
3121.
     8. It is of the essence of the contract, that there should be an actual
delivery of the thing. 6 Mass. 422; 15 Mass. 477 14 Mass. 352; 2 Caines' C.
Err. 200; 2 Kent's Com. 452; Bac. Abr. Bailment, B; 2 Rolle R. 439; 6 Pick.
R. 59, 60; Pothier, De Nantissement, n. 8, 9; Louis. Code, 3129. What will
amount to a delivery, is matter of law. See Delivery.
     9. It is essential that the thing should be delivered as a security for
some debt or engagement. Story on Bailm. Sec. 300. And see 3 Cranch, 73; 7
Cranch, 34; 2 John. Ch. R. 309; 1 Atk. 236; Prec. in Ch. 419; 2 Vern. 691;
Gilb. Eq. R. 104; 6 Mass. 339; Pothier, Nantissement, n. 12; Civ. Code of
Lo. art. 3119; Code Civ. art. 2076.
    10. In virtue of the pawn the pawnee acquires, by the common law, a
special property in the thing, and is entitled to the possession of it
exclusively, during the time and for the objects for which it is pledged. 2
Bl. Com. 396; Jones' Bailm. 80; Owen R. 123, 124; 1 Bulst. 29; Yelv. 178
Cro. Jac. 244; 2 Ld. Raym. 909, 916; Bac. Abr. Bailment, B; 1 Dane's Abr.
ch. 17, art. 4, SSSS 1, 6; Code Civ. art. 2082; Civ. Code of Lo. art. 3131.
And he has a right to sell the pledge, when there has been a default in the
pledger in complying with his engagement. Such a default does not divest the
general property of the pawner, but still leaves him a right of redemption.
But if the, pledge is not redeemed within the stipulated time, by a due
performance of the contract for which it is a security, the pawnee has then
a right to sell it, in order to have his debt or indemnity. And if there is
no stipulated time for the payment of the debt, but the pledge is for an
indefinite period, the pawnee has a right, upon request, to a prompt
fulfillment of the agreement; and if the pawner refuses to comply, the
pawnee may, upon demand and notice to the pawner, require the pawn to be
sold. 2 Kent's Com. 452; Story on Bailm. 308.
    11. The pawnee is bound to use ordinary diligence in keeping the pawn,
and consequently is liable for ordinary neglect in keeping it. Jones' Bailm.
75; 2 Kent's Com. 451; 1 Dane's Abr. ch. 17, art. 12; 2 Ld. Raym, 909, 916;
Domat B 1, tit. 1, Sec. 4, n. 1.
    12. The pawner has the right of redemption. If the pledge is conveyed by
way of mortgage, and thus passes the legal title, unless he redeems the
pledge at a stipulated time, the title of the pledge becomes absolute at
law; and the pledger has no remedy at law, but only a remedy in equity to
redeem. 2 Ves. Jr. 378; 2 Caines' C. Err. 200. If, however, the transaction
is not a transfer of ownership, but a mere pledge, as the pledger has never
parted with the general title, he may, at law, redeem, notwithstanding he
has not strictly complied with the condition of his contract. Com. Dig.
Mortgage, B; 1 Pow. on Mortg. by Coventry & Land. 401, and notes, ibid. See
further, as to the pawner's right of redemption, Story on Bailm. Sec. 345 to
349.
    13. By the act of pawning, the pawner enters into an implied agreement
or warranty that he is the owner of the property pawned, and that he has a
good right to pass the title. Story on Bailm. Sec. 354.
    14. As to the manner of extinguishing the contract of pledge or mortgage
of personal property, see Story on Bailm. 359 to 366.



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

PLEDGE, contracts. He who becomes security for another, and, in this sense,
every one who becomes bail for another is a pledge. 4 Inst. 180 Com. Dig. B.
See Pledges.