The Collaborative International Dictionary of English v.0.48:

Bargain \Bar"gain\, v. t. [imp. & p. p. Bargained (?); p. pr.
   & vb. n. Bargaining.]
   To transfer for a consideration; to barter; to trade; as, to
   bargain one horse for another.
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   To bargain away, to dispose of in a bargain; -- usually
      with a sense of loss or disadvantage; as, to bargain away
      one's birthright. "The heir . . . had somehow bargained
      away the estate." --G. Eliot.
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The Collaborative International Dictionary of English v.0.48:

Bargain \Bar"gain\, n. [OE. bargayn, bargany, OF. bargaigne,
   bargagne, prob. from a supposed LL. barcaneum, fr. barca a
   boat which carries merchandise to the shore; hence, to
   traffic to and fro, to carry on commerce in general. See
   Bark a vessel. ]
   1. An agreement between parties concerning the sale of
      property; or a contract by which one party binds himself
      to transfer the right to some property for a
      consideration, and the other party binds himself to
      receive the property and pay the consideration.
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            A contract is a bargain that is legally binding.
                                                  --Wharton.
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   2. An agreement or stipulation; mutual pledge.
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            And whon your honors mean to solemnize
            The bargain of your faith.            --Shak.
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   3. A purchase; also ( when not qualified), a gainful
      transaction; an advantageous purchase; as, to buy a thing
      at a bargain.
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   4. The thing stipulated or purchased; also, anything bought
      cheap.
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            She was too fond of her most filthy bargain. --Shak.
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   Bargain and sale (Law), a species of conveyance, by which
      the bargainor contracts to convey the lands to the
      bargainee, and becomes by such contract a trustee for and
      seized to the use of the bargainee. The statute then
      completes the purchase; i. e., the bargain vests the use,
      and the statute vests the possession. --Blackstone.

   Into the bargain, over and above what is stipulated;
      besides.

   To sell bargains, to make saucy (usually indelicate)
      repartees. [Obs.] --Swift.

   To strike a bargain, to reach or ratify an agreement. "A
      bargain was struck." --Macaulay.
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   Syn: Contract; stipulation; purchase; engagement.
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The Collaborative International Dictionary of English v.0.48:

Bargain \Bar"gain\, v. i. [OE. barganien, OF. bargaigner, F.
   barguigner, to hesitate, fr. LL. barcaniare. See Bargain,
   n.]
   To make a bargain; to make a contract for the exchange of
   property or services; -- followed by with and for; as, to
   bargain with a farmer for a cow.
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         So worthless peasants bargain for their wives. --Shak.
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WordNet (r) 3.0 (2006):

bargain
    n 1: an agreement between parties (usually arrived at after
         discussion) fixing obligations of each; "he made a bargain
         with the devil"; "he rose to prominence through a series of
         shady deals" [syn: bargain, deal]
    2: an advantageous purchase; "she got a bargain at the auction";
       "the stock was a real buy at that price" [syn: bargain,
       buy, steal]
    v 1: negotiate the terms of an exchange; "We bargained for a
         beautiful rug in the bazaar" [syn: dicker, bargain]
    2: come to terms; arrive at an agreement