Index -
A published interest rate not controlled by the lender to which the interest rate on an Adjustable Rate Mortgage (ARM) is tied. The index and the interest rate linked to it may increase or decrease.

Interest -
Consideration in the form of money paid for the use of money, usually expressed as an annual percentage. Also, a right, share, or title in property.

Interest Only -
A term loan arrangement calling for payments of interest only, not to include any amount for principal.

Interest Rate -
The percentage of an amount of money that's paid for its use over a specified time period.

Interest Rate Swap -
A transaction between two parties, in which each agrees to exchange payments tied to different interest rates or indices for a specified period of time.

Intermediate-Term Mortgage -
A mortgage loan with a stated maturity at the time of purchase that it is equal to or less than 20 years.