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.
duration of action. Therapeutics The length of time that a particular drug is effective. duÂ·raÂ·tion of acÂ·tion. (dÅ­r-Ä'shÅ­n ak'shÅ­n) The amount of time that a measurable drug effect persists.