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

BARGAIN AND SALE, conveyancing, contracts. A contract in writing to convey
lands to another person; or rather it is the sale of a use therein. In
strictness it is not an absolute conveyance of the seisin, as a feoffment.
Watk. Prin. Conv. by Preston, 190, 191. The consideration must be of money
or money's worth. Id. 237.
     2. In consequence of this conveyance a use arises to a bargainee, and
the statute 27 Henry VIII. immediately transfers the20legal estate and
possession to him.
     3. A bargain and sale, may be in fee, for life, or for years.
     4. The proper and technical words of this conveyance are bargain and
sale, but any other words that would have been sufficient to raise a use,
upon a valuable consideration, before the statute, are now sufficient to
constitute a good bargain and sale. Proper words of limitation must,
however, be inserted. Cruise Dig. tit. 32, c. 9; Bac. Ab. h. t. Com. Dig. h.
t.; and the cases there cited; Nels. Ab. h. t. 2 Bl. Com. 338.
     5. This is the most common mode of conveyance in the United States. 4
Kent, Com. 483; 3 Pick. R. 529; 3 N. H. Rep. 260; 6 Harr. & John. 465; 3
Wash. C. C. Rep. 376; 4 Mass. R. 66; 4 Yeates, R. 295; 1 Yeates, R. 828; 3
John. R. 388; 4 Cowen's R. 325; 10 John. R. 456, 505; 3 N. H. Rep. 261; 14
John. R. 126; 2 Harr. & John. 230; 2 Bouv. Inst. n. 207 7 8.