geometric progression A sequence of numbers in which each number is multiplied by the same factor to obtain the next number in the sequence. In a geometric progression, the ratio of any two adjacent numbers is the same. An example is 5, 25, 125, 625, ... , where each number is multiplied by 5 to obtain the following number, and the ratio of any number to the next number is always 1 to 5. Compare arithmetic progression.
In mathematics, a sequence of numbers in which each number is obtained from the previous one by multiplying by a constant. For example, the sequence 1, 2, 4, 8, 16, 32 &ellipsis; (in which each number is multiplied by 2 to get the next one) is a geometric progression.
Note: Many processes involving growth and spreading, such as population increases, can be described as geometric progressions.