The Collaborative International Dictionary of English v.0.48:

Income \In"come\, n.
   1. A coming in; entrance; admittance; ingress; infusion.
      [Obs.] --Shak.
      [1913 Webster]

            More abundant incomes of light and strength from
            God.                                  --Bp. Rust.
      [1913 Webster]

            At mine income I louted low.          --Drant.
      [1913 Webster]

   2. That which is caused to enter; inspiration; influence;
      hence, courage or zeal imparted. [R.]
      [1913 Webster]

            I would then make in and steep
            My income in their blood.             --Chapman.
      [1913 Webster]

   3. That gain which proceeds from labor, business, property,
      or capital of any kind, as the produce of a farm, the rent
      of houses, the proceeds of professional business, the
      profits of commerce or of occupation, or the interest of
      money or stock in funds, etc.; revenue; receipts; salary;
      especially, the annual receipts of a private person, or a
      corporation, from property; as, a large income.
      [1913 Webster]

            No fields afford
            So large an income to the village lord. --Dryden.
      [1913 Webster]

   4. (Physiol.) That which is taken into the body as food; the
      ingesta; -- sometimes restricted to the nutritive, or
      digestible, portion of the food. See Food. Opposed to
      output.
      [1913 Webster]

   Income bond, a bond issued on the income of the corporation
      or company issuing it, and the interest of which is to be
      paid from the earnings of the company before any dividends
      are made to stockholders; -- issued chiefly or exclusively
      by railroad companies.

   Income tax, a tax upon a person's incomes, emoluments,
      profits, etc., or upon the excess beyond a certain amount.

   Syn: Gain; profit; proceeds; salary; revenue; receipts;
        interest; emolument; produce.
        [1913 Webster]

WordNet (r) 3.0 (2006):

income
    n 1: the financial gain (earned or unearned) accruing over a
         given period of time [ant: expenditure, outgo,
         outlay, spending]

Moby Thesaurus II by Grady Ward, 1.0:

124 Moby Thesaurus words for "income":
   access, admission, avails, base pay, box office, capital gains,
   cleanup, clear profit, commissions, compensation, credit, credits,
   dismissal wage, disposable income, dividend, dividends,
   earned income, earnings, entrance, entree, entry, escalator clause,
   escalator plan, filthy lucre, financial remuneration, gain, gains,
   gate, gate receipts, get, gettings, gleanings, gross, gross income,
   gross profit, gross receipts, guaranteed annual wage, hire, hoard,
   import, importation, importing, incoming, infiltration, ingoing,
   ingress, ingression, input, insertion, insinuation, intake,
   interest, interpenetration, introduction, introgression, intrusion,
   killing, leakage, living wage, lucre, make, makings, minimum wage,
   neat profit, net, net income, net profit, net receipts, output,
   paper profits, pay, pay and allowances, payment, payroll, pelf,
   penetration, percentage, percolation, perk, perks, perquisite,
   pickings, portal-to-portal pay, proceeds, produce, profit, profits,
   purchasing power, rake-off, real wages, receipt, receipts,
   receivables, reception, remuneration, return, returns, revenue,
   royalties, salary, seepage, severance pay, sliding scale, store,
   take, take-home, take-home pay, take-in, takings, taxable income,
   total compensation, unearned income, wage, wage control,
   wage freeze, wage reduction, wage rollback, wage scale, wages,
   wages after deductions, wages after taxes, wealth, winnings,
   yield



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

INCOME. The gain which proceeds from property, labor, or business; it is
applied particularly to individuals; the income of the government is usually
called revenue.
     2. It has been holden that a devise of the income of land, is in effect
the same as a devise of the land itself. 9 Mass. 372; 1 Ashm. 136.



The Devil's Dictionary (1881-1906):

INCOME, n.  The natural and rational gauge and measure of
respectability, the commonly accepted standards being artificial,
arbitrary and fallacious; for, as "Sir Sycophas Chrysolater" in the
play has justly remarked, "the true use and function of property (in
whatsoever it consisteth -- coins, or land, or houses, or merchant-
stuff, or anything which may be named as holden of right to one's own
subservience) as also of honors, titles, preferments and place, and
all favor and acquaintance of persons of quality or ableness, are but
to get money.  Hence it followeth that all things are truly to be
rated as of worth in measure of their serviceableness to that end; and
their possessors should take rank in agreement thereto, neither the
lord of an unproducing manor, howsoever broad and ancient, nor he who
bears an unremunerate dignity, nor yet the pauper favorite of a king,
being esteemed of level excellency with him whose riches are of daily
accretion; and hardly should they whose wealth is barren claim and
rightly take more honor than the poor and unworthy."