The act or an instance of iterating; repetition. A form, adaption, or version of something: the latest iteration of a popular app. Mathematics A computational procedure in which a cycle of operations is repeated, often to approximate the desired result more closely. Computers The process of repeating a set of instructions a specified number of times or until a specific result is achieved. One cycle of a set of instructions to be repeated: After ten iterations, the program exited the loop.