Definitions of YIELD for you and the rest of your mates
http://www.investopedia.com/terms/y/yield.asp
The income return on an investment. This refers to the interest or dividends received from a security and is usually expressed annually as a percentage based on the investment's cost, its current market value or its face value.
This seemingly simple term, without a qualifier, can be rather confusing to investors.
For example, there are two stock dividend yields. If you buy a stock for $30 (cost basis) and its current price and annual dividend is $33 and $1, respectively, the "cost yield" will be 3.3% ($1/$30) and the "current yield" will be 3% ($1/$33).
Bonds have four yields: coupon (the bond interest rate fixed at issuance), current (the bond interest rate as a percentage of the current price of the bond), and yield to maturity (an estimate of what an investor will receive if the bond is held to its maturity date). Non-taxable municipal bonds will have a tax-equivalent (TE) yield determined by the investor's tax bracket.
Mutual fund yields are an annual percentage measure of income (dividends and interest) earned by the fund's portfolio, net of the fund's expenses. In addition, the "SEC yield" is an indicator of the percentage yield on a fund based on a 30-day period.
http://www.invested.com.au/71/rental-yield-2659/
Definition:
Yield is a measure of the percentage of income return you get from an asset. This measure applies to a number of assets, but especially shares and real estate.
For real estate, the yield calculation is the percentage of rental income for the purchase price. The yield is calculated by dividing the gross annual rental income by the purchase price (or the current valuation).
Example, if a property is rented for $315 per week, and the purchase price is $409,000, then the yield is (315*52)/409000 = 4.01%