kickback

kickback
    n 1: a commercial bribe paid by a seller to a purchasing agent
         in order to induce the agent to enter into the transaction
    

kickback \kick"back`\, n.
   1. recoil, of a gun or machine, as in older automobile
      engines when started by turning a crank.
      [PJC]

   2. A secret, and usually illegal, payment, by a recipient of
      money paid for goods or services, to a facilitator of the
      transaction, of a portion of that money; specifically, any
      portion of a gain made by the seller in a commercial
      transaction which is returned surreptitiously and
      illegally to a person (such as a purchasing agent) who
      authorized or recommended the purchase. It is generally
      considered a form of bribe.
      [PJC]
    

63 Moby Thesaurus words for "kickback":
      abatement, agio, allowance, backfire, backlash, backlashing,
      bank discount, boomerang, bounce, bound, breakage, bribe, carom,
      cash discount, chain discount, charge-off, commission,
      compensation, concession, contrecoup, cut, deduction, depreciation,
      discount, drawback, kick, payola, penalty, penalty clause,
      percentage, premium, price reduction, price-cut, rebate,
      rebatement, rebound, rebuff, recalcitration, recoil, recoupment,
      reduction, refund, refundment, reimbursement, repayment,
      repercussion, repulse, resilience, restitution, return, reward,
      ricochet, rollback, salvage, setoff, share, spring, tare,
      time discount, trade discount, tret, underselling, write-off