Money received, esp. on a regular basis, for work or through investments. Wages, dividends, realized capital appreciation, royalties, and interest, are income.  Gain derived from capital, from labor, or from both combined, including profit gained through sale or conversion of capital. Any increase in wealth — whether through wages, benefits, bonuses, sale of stock or other property at a profit, bets won, lucky finds, awards of punitive damages in a lawsuit, are all within the definition of income. Income arising either from rents of real estate or from personal property, including invested personal property, bonds, stocks, and investments of all kinds. 
As investors use the term, income includes the total return from an asset. The change in value of an investment over a given period, assuming reinvestment of any dividends and capital gain distributions, expressed as a percentage of the initial investment.  The total return includes dividends, capital gains distributions, and the increase in the net asset value of the property. 
Incoming was originally of game approaching the hunter. c.1300, "entrance, arrival," lit. "what enters," "money made through business or labor," first recorded 1601.