The Collaborative International Dictionary of English v.0.48:

Pay \Pay\, v. t. [imp. & p. p. Paid (p[=a]d); p. pr. & vb. n.
   Paying.] [OE. paien, F. payer, fr. L. pacare to pacify,
   appease, fr. pax, pacis, peace. See Peace.]
   1. To satisfy, or content; specifically, to satisfy (another
      person) for service rendered, property delivered, etc.; to
      discharge one's obligation to; to make due return to; to
      compensate; to remunerate; to recompense; to requite; as,
      to pay workmen or servants.
      [1913 Webster]

            May no penny ale them pay [i. e., satisfy]. --P.
                                                  Plowman.
      [1913 Webster]

            [She] pays me with disdain.           --Dryden.
      [1913 Webster]

   2. Hence, figuratively: To compensate justly; to requite
      according to merit; to reward; to punish; to retort or
      retaliate upon.
      [1913 Webster]

            For which, or pay me quickly, or I'll pay you. --B.
                                                  Jonson.
      [1913 Webster]

   3. To discharge, as a debt, demand, or obligation, by giving
      or doing what is due or required; to deliver the amount or
      value of to the person to whom it is owing; to discharge a
      debt by delivering (money owed). "Pay me that thou owest."
      --Matt. xviii. 28.
      [1913 Webster]

            Have patience with me, and I will pay thee all.
                                                  --Matt. xviii.
                                                  26.
      [1913 Webster]

            If they pay this tax, they starve.    --Tennyson.
      [1913 Webster]

   4. To discharge or fulfill, as a duy; to perform or render
      duty, as that which has been promised.
      [1913 Webster]

            This day have I paid my vows.         --Prov. vii.
                                                  14.
      [1913 Webster]

   5. To give or offer, without an implied obligation; as, to
      pay attention; to pay a visit.
      [1913 Webster]

            Not paying me a welcome.              --Shak.
      [1913 Webster]

   To pay off.
      (a) To make compensation to and discharge; as, to pay off
          the crew of a ship.
      (b) To allow (a thread, cord, etc.) to run off; to unwind.
      (c) to bribe.

   To pay one's duty, to render homage, as to a sovereign or
      other superior.

   To pay out (Naut.), to pass out; hence, to slacken; to
      allow to run out; as, to pay out more cable. See under
      Cable.

   To pay the piper, to bear the cost, expense, or trouble.
      [Colloq.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

paying \paying\ n.
   1. the act of paying money.

   Syn: payment, defrayal, defrayment.
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

paying \paying\ adj.
   yielding material gain or profit; as, paying investments.
   [Ant: unprofitable]

   Syn: profitable.
        [WordNet 1.5]

   2. providing a salary for work performed; as, a paying job.
      [prenominal] [Ant: unpaid]

   Syn: compensable, remunerative, salaried, stipendiary,
        gainful.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

paying
    adj 1: yielding a fair profit [syn: gainful, paid, paying]
    2: for which money is paid; "a paying job"; "remunerative work";
       "salaried employment"; "stipendiary services" [syn:
       compensable, paying(a), remunerative, salaried,
       stipendiary]

Moby Thesaurus II by Grady Ward, 1.0:

69 Moby Thesaurus words for "paying":
   acquitment, acquittal, acquittance, advantageous, amortization,
   amortizement, banausic, binder, breadwinning, cash, cash payment,
   clearance, compensating, compensative, compensatory, debt service,
   defrayal, defrayment, deposit, disbursal, discharge, doling out,
   down payment, earnest, earnest money, fat, gainful, good,
   hire purchase, hire purchase plan, installment, installment plan,
   interest payment, liquidation, lucrative, moneymaking,
   monthly payments, never-never, paying off, paying out, paying up,
   payment, payment in kind, payoff, prepayment, productive,
   profitable, quarterly payments, quittance, regular payments,
   remittance, remunerative, reparative, repaying, retirement,
   retributive, retributory, rewardful, rewarding, satisfaction,
   satisfying, settlement, sinking-fund payment, solvent, sound,
   spot cash, weekly payments, well-paying, worthwhile