From The Collaborative International Dictionary of English v.0.48:

Revenue \Rev"e*nue\, n. [F. revenu, OF. revenue, fr. revenir to
   return, L. revenire; pref. re- re- + venire to come. See
   Come.]
   1. That which returns, or comes back, from an investment; the
      annual rents, profits, interest, or issues of any species
      of property, real or personal; income.
      [1913 Webster]

            Do not anticipate your revenues and live upon air
            till you know what you are worth.     --Gray.
      [1913 Webster]

   2. Hence, return; reward; as, a revenue of praise.
      [1913 Webster]

   3. The annual yield of taxes, excise, customs, duties, rents,
      etc., which a nation, state, or municipality collects and
      receives into the treasury for public use.
      [1913 Webster]

   Revenue cutter, an armed government vessel employed to
      enforce revenue laws, prevent smuggling, etc.
      [1913 Webster]

From WordNet (r) 2.0:

revenue
     n 1: the entire amount of income before any deductions are made
          [syn: gross, receipts]
     2: government income due to taxation [syn: tax income, taxation,
         tax revenue]

From Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "revenue":
   avails, box office, commissions, credit, credits,
   disposable income, dividend, dividends, earned income, earnings,
   gain, gains, gate, gate receipts, get, gross, gross income,
   gross receipts, income, intake, interest, make, net, net income,
   net receipts, output, proceeds, produce, profit, profits, receipt,
   receipts, receivables, returns, royalties, salary, take, take-in,
   takings, unearned income, wages, yield

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

REVENUE. The income of the government arising from taxation, duties, and the 
like; and, according to some correct lawyers, under the idea of revenue is 
also included the proceeds of the sale of stocks, lands, and other property 
owned by the government. Story, Const. Sec. 877. Vide Money Bills. By 
revenue is also understood the income of private individuals and 
corporations.