See more synonyms on Thesaurus.com. noun. 1. a written promise to pay a specified sum of money to a designated person or to his or her order, or to the bearer of the note, at a fixed time or on demand. 2. a written promise to do or provide something, usually presented as a gift and claimable when or however the recipient chooses.
DEFINITION of 'Duration'. A measure of the sensitivity of the price (the value of principal) of a fixed-income investment to a change in interest rates. Duration is expressed as a number of years. Rising interest rates mean falling bond prices, while declining interest rates mean rising bond prices.
Macaulay duration is a time measure with units in years, and really makes sense only for an instrument with fixed cash flows. For a standard bond the Macaulay duration will be between 0 and the maturity of the bond. It is equal to the maturity if and only if the bond is a zero-coupon bond. Modified duration, on the other hand, is a derivative (rate of change) of price and measures the percentage rate of change of price with respect to yield.