1) any and all, partial or total right to property or for the use of property, including an easement to pass over a neighboring parcel of land, the right to drill for oil, a possibility of acquiring title upon the happening of some event, or outright title. while most often referring to real property, one may have an interest in a business, a bank account or any article. 2) the financial amount (money) paid by someone else for the use of a person’s money, as on a loan or debt, on a savings account in a bank, on a certificate of deposit, promissory note or the amount due on a judgment. interest is usually stated in writing at the time the money is loaned. there are variable rates of interest, particularly on savings accounts which depend on funding from the federal reserve or other banks and are controlled by the prevailing interest rates on those funds. maximum interest rates on loans made by individuals are controlled by statute. to charge more than that rate is usury, the penalty for which may be the inability of a creditor to collect through the courts. the interest rates demanded by lending institutions are not so restricted. the maximum legal interest often granted by the courts on judgments is set by the law of the state. simple interest is the annual rate charged for a loan, and compound interest includes interest upon interest during the year. 3) one’s involvement in business, activities or with an individual which is sufficient to create doubt about a witness being objective-damaging his/her credibility. 4) one’s involvement in business, activities or with an individual which is sufficient connection to give a person “standing” (the right based on interest in the outcome of the lawsuit or petition) to bring a lawsuit on a particular matter or act on behalf of other people.