The Collaborative International Dictionary of English v.0.48:

Sell \Sell\ (s[e^]l), v. t. [imp. & p. p. Sold (s[=o]ld); p.
   pr. & vb. n. Selling.] [OE. sellen, sillen, AS. sellan,
   syllan, to give, to deliver; akin to OS. sellian, OFries.
   sella, OHG. sellen, Icel. selja to hand over, to sell, Sw.
   s[aum]lja to sell, Dan. s[ae]lge, Goth. saljan to offer a
   sacrifice; all from a noun akin to E. sale. Cf. Sale.]
   1. To transfer to another for an equivalent; to give up for a
      valuable consideration; to dispose of in return for
      something, especially for money. It is the correlative of
      buy.
      [1913 Webster]

            If thou wilt be perfect, go and sell that thou hast,
            and give to the poor.                 --Matt. xix.
                                                  21.
      [1913 Webster]

            I am changed; I'll go sell all my land. --Shak.
      [1913 Webster]

   Note: Sell is corellative to buy, as one party buys what the
         other sells. It is distinguished usually from exchange
         or barter, in which one commodity is given for another;
         whereas in selling the consideration is usually money,
         or its representative in current notes.
         [1913 Webster]

   2. To make a matter of bargain and sale of; to accept a price
      or reward for, as for a breach of duty, trust, or the
      like; to betray.
      [1913 Webster]

            You would have sold your king to slaughter. --Shak.
      [1913 Webster]

   3. To impose upon; to trick; to deceive; to make a fool of;
      to cheat. [Slang] --Dickens.
      [1913 Webster]

   To sell one's life dearly, to cause much loss to those who
      take one's life, as by killing a number of one's
      assailants.

   To sell (anything) out, to dispose of it wholly or
      entirely; as, he had sold out his corn, or his interest in
      a business.
      [1913 Webster]

WordNet (r) 3.0 (2006):

selling
    n 1: the exchange of goods for an agreed sum of money [syn:
         selling, merchandising, marketing]

Moby Thesaurus II by Grady Ward, 1.0:

80 Moby Thesaurus words for "selling":
   accouterment, allurement, armament, blandishment, cajolement,
   cajolery, catering, chandlery, coaxing, conning,
   consumer preference study, consumer research, consumer survey,
   direct-mail selling, endowment, engagement, enlistment, equipment,
   exhortation, finding, fitting out, furnishing, furnishment,
   hard sell, hawking, high-pressure salesmanship, hortation,
   huckstering, inducement, investment, jawboning, jobbing, lobbying,
   logistics, low-pressure salesmanship, mail-order selling, market,
   market research, marketing, marketing research, merchandising,
   outfitting, peddling, persuasion, preaching, preachment,
   preparation, procurement, promotion, providing, provision,
   provisioning, purveyance, reinforcement, replenishment, resupply,
   retail, retailing, sales, sales campaign, sales promotion,
   sales talk, salesmanship, sellout, snow job, soft sell, soft soap,
   solicitation, suasion, subsidization, subsidy, subvention, supply,
   supplying, sweet talk, victualing, wheedling, wholesale,
   wholesaling, working on